fix(m4-1b-ii): complete §1.1 retirement in MCP content filters + review-round-1 witnesses

GLM round-1 findings on PR #1465:
- BLOCKING 1: remove role-keyed content widening from mcp.service.ts —
  isGlobalAdminActor/isTenantAdminActor/matchesTenant and every
  short-circuit keyed on users.role are gone; project/mission/task
  visibility is ownership + derived membership only, task create scope
  is unconditional. Spec test rewritten to witness that admin-role and
  platform-admin-role actors see only owned content.
- MINOR 2: writer-coverage header updated to the non-empty allowlist.
- MINOR 3: §6.9 witness — a directory-listed company still refuses
  non-granted callers (granted-read exclusion + mutation oracle).
- MINOR 4: §6.4 commit legs for renameCompany (previousName in the
  audited event) and direct revokeGrant (row deletion + grant_revoke).

apps/gateway/src/__tests__/hierarchy-route-inventory.test.ts

@@ -0,0 +1,133 @@
+import { RequestMethod, type Type } from '@nestjs/common';
+import { describe, expect, it } from 'vitest';
+import { AppModule } from '../app.module.js';
+import { HierarchyModule } from '../hierarchy/hierarchy.module.js';
+
+/**
+ * Hierarchy route inventory (contract 1 §6.3).
+ *
+ * The hierarchy command family is a CLOSED enumeration asserted here, not a
+ * prose claim: every hierarchy-flavored route the AppModule graph declares
+ * must appear in HIERARCHY_COMMAND_FAMILY, and vice versa. Adding or
+ * removing a hierarchy route without updating this inventory (and its
+ * witnesses) fails CI first. This replaces the M4-1b-i zero-routes
+ * baseline.
+ */
+
+interface RouteEntry {
+  method: string;
+  path: string;
+  controller: string;
+}
+
+/** Module-metadata entry: a module class or a DynamicModule-shaped object. */
+type ModuleEntry =
+  | Type<unknown>
+  | { module: Type<unknown>; imports?: unknown[]; controllers?: Type<unknown>[] };
+
+function collectControllers(root: ModuleEntry): Type<unknown>[] {
+  const visited = new Set<unknown>();
+  const controllers: Type<unknown>[] = [];
+  const walk = (entry: ModuleEntry | undefined | null): void => {
+    if (!entry || visited.has(entry)) return;
+    visited.add(entry);
+    const moduleClass = typeof entry === 'function' ? entry : entry.module;
+    // Entries with no resolvable class (forwardRef wrappers, async dynamic
+    // modules) carry no decorator metadata to read here.
+    if (typeof moduleClass !== 'function') return;
+    if (visited.has(moduleClass) && typeof entry !== 'function') return;
+    visited.add(moduleClass);
+    // 'controllers' / 'imports' are the metadata keys the @Module decorator writes.
+    const declared = (Reflect.getMetadata('controllers', moduleClass) ?? []) as Type<unknown>[];
+    controllers.push(...declared);
+    if (typeof entry !== 'function' && entry.controllers) controllers.push(...entry.controllers);
+    const imports = [
+      ...((Reflect.getMetadata('imports', moduleClass) ?? []) as ModuleEntry[]),
+      ...(typeof entry !== 'function' ? ((entry.imports ?? []) as ModuleEntry[]) : []),
+    ];
+    for (const imported of imports) walk(imported);
+  };
+  walk(root);
+  return controllers;
+}
+
+function routesOf(controller: Type<unknown>): RouteEntry[] {
+  // 'path' on the class is the @Controller prefix; 'path'/'method' on a
+  // handler are written by the @Get/@Post/... route decorators.
+  const base = (Reflect.getMetadata('path', controller) ?? '') as string | string[];
+  const bases = Array.isArray(base) ? base : [base];
+  const routes: RouteEntry[] = [];
+  const prototype = controller.prototype as Record<string, unknown>;
+  for (const name of Object.getOwnPropertyNames(prototype)) {
+    if (name === 'constructor') continue;
+    const handler = Object.getOwnPropertyDescriptor(prototype, name)?.value;
+    if (typeof handler !== 'function') continue;
+    const method = Reflect.getMetadata('method', handler) as number | undefined;
+    if (method === undefined) continue;
+    const sub = (Reflect.getMetadata('path', handler) ?? '/') as string;
+    for (const prefix of bases) {
+      const path = `/${prefix}/${sub}`.replace(/\/+/g, '/').replace(/(.)\/$/, '$1');
+      routes.push({
+        method: RequestMethod[method] ?? String(method),
+        path,
+        controller: controller.name,
+      });
+    }
+  }
+  return routes;
+}
+
+/**
+ * The closed command family (contract 1 §5, M4-1b-ii). Every entry is a
+ * mutation audited via the M4-1b-i path or one of the two ratified reads
+ * (granted companies, the §2.8 directory carve-out).
+ */
+const HIERARCHY_COMMAND_FAMILY = [
+  'POST /api/hierarchy/companies',
+  'GET /api/hierarchy/companies',
+  'GET /api/hierarchy/companies/directory',
+  'POST /api/hierarchy/companies/:id/rename',
+  'POST /api/hierarchy/companies/:id/visibility',
+  'DELETE /api/hierarchy/companies/:id',
+  'POST /api/hierarchy/estates',
+  'POST /api/hierarchy/estates/:id/rename',
+  'POST /api/hierarchy/estates/:id/transfer',
+  'DELETE /api/hierarchy/estates/:id',
+  'POST /api/hierarchy/platform-projects',
+  'POST /api/hierarchy/platform-projects/:id/rename',
+  'POST /api/hierarchy/platform-projects/:id/transfer',
+  'DELETE /api/hierarchy/platform-projects/:id',
+  'POST /api/hierarchy/grants',
+  'POST /api/hierarchy/grants/:id/change',
+  'DELETE /api/hierarchy/grants/:id',
+] as const;
+
+describe('hierarchy route inventory (§6.3)', () => {
+  const inventory = collectControllers(AppModule).flatMap(routesOf);
+
+  it('control: the enumeration sees the known route surface', () => {
+    const paths = inventory.map((r) => `${r.method} ${r.path}`);
+    expect(paths).toContain('GET /health');
+    expect(paths).toContain('POST /api/workspaces');
+    expect(paths).toContain('GET /api/teams');
+    expect(inventory.length).toBeGreaterThan(20);
+  });
+
+  it('the hierarchy surface is exactly the declared command family', () => {
+    const hierarchyRoutes = inventory
+      .filter((r) => /hierarch|compan|estate|platform[-_]?project/i.test(r.path))
+      .map((r) => `${r.method} ${r.path}`)
+      .sort();
+    expect(hierarchyRoutes).toEqual([...HIERARCHY_COMMAND_FAMILY].sort());
+  });
+
+  it('every command-family route lives on HierarchyController inside HierarchyModule', () => {
+    const controllers = collectControllers(HierarchyModule);
+    expect(controllers.map((c) => c.name)).toEqual(['HierarchyController']);
+    const declared = controllers
+      .flatMap(routesOf)
+      .map((r) => `${r.method} ${r.path}`)
+      .sort();
+    expect(declared).toEqual([...HIERARCHY_COMMAND_FAMILY].sort());
+  });
+});

apps/gateway/src/app.module.ts

@@ -24,6 +24,7 @@ import { GCModule } from './gc/gc.module.js';
 import { HarnessModule } from './harness/harness.module.js';
 import { ReloadModule } from './reload/reload.module.js';
 import { WorkspaceModule } from './workspace/workspace.module.js';
+import { HierarchyModule } from './hierarchy/hierarchy.module.js';
 import { QueueModule } from './queue/queue.module.js';
 import { FederationModule } from './federation/federation.module.js';
 import { ThrottlerGuard, ThrottlerModule } from '@nestjs/throttler';
@@ -65,6 +66,7 @@ const federationEnabled = loadConfig(resolveGatewayConfigPath()).tier === 'feder
     QueueModule,
     ReloadModule,
     WorkspaceModule,
+    HierarchyModule,
     ...(federationEnabled ? [FederationModule] : []),
   ],
   controllers: [HealthController],

apps/gateway/src/commands/command-authorization.service.spec.ts

@@ -61,6 +61,33 @@ describe('CommandAuthorizationService', () => {
     ).toBe(false);
   });
 
+  it('denies non-admin scopes to a platform admin (contract 2 §1.1 bypass retirement)', async (): Promise<void> => {
+    const service = createService('admin');
+    for (const scope of ['core', 'agent', 'skill', 'plugin'] as const) {
+      const command: CommandDef = { ...adminCommand, name: `probe-${scope}`, scope };
+      expect(
+        (await service.authorize(command, { ...payload, command: command.name }, 'admin-1'))
+          .allowed,
+      ).toBe(false);
+    }
+  });
+
+  it('allows member core/agent scopes and denies skill/plugin (deny-by-default)', async (): Promise<void> => {
+    const service = createService('member');
+    for (const [scope, allowed] of [
+      ['core', true],
+      ['agent', true],
+      ['skill', false],
+      ['plugin', false],
+    ] as const) {
+      const command: CommandDef = { ...adminCommand, name: `probe-${scope}`, scope };
+      expect(
+        (await service.authorize(command, { ...payload, command: command.name }, 'member-1'))
+          .allowed,
+      ).toBe(allowed);
+    }
+  });
+
   it('denies a malformed durable approval expiry instead of treating it as unexpired', async (): Promise<void> => {
     const entries = new Map<string, string>();
     const action = {

apps/gateway/src/commands/command-authorization.service.ts

@@ -154,8 +154,15 @@ export class CommandAuthorizationService {
     return role === 'admin' || role === 'member' || role === 'viewer' ? role : null;
   }
 
+  /**
+   * Contract 2 §1.1: platform admin confers instance administration only —
+   * the former admin-passes-every-scope short-circuit is retired. Admin
+   * reaches exactly the admin scope; core/agent scopes belong to the member
+   * role; skill/plugin scopes stay deny-for-all until a grant mapping names
+   * them (§3.1 deny-by-default).
+   */
   private hasScope(role: CommandRole, scope: CommandDef['scope']): boolean {
-    if (role === 'admin') return true;
+    if (scope === 'admin') return role === 'admin';
     return role === 'member' && (scope === 'core' || scope === 'agent');
   }
 

apps/gateway/src/hierarchy/hierarchy-audit.integration.test.ts

@@ -0,0 +1,247 @@
+import { mkdtemp, rm } from 'node:fs/promises';
+import { randomUUID } from 'node:crypto';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { Test, type TestingModule } from '@nestjs/testing';
+import {
+  companies,
+  createPgliteDb,
+  eq,
+  estates,
+  hierarchyAuditEvents,
+  hierarchyOutbox,
+  platformProjects,
+  runPgliteMigrations,
+  type DbHandle,
+} from '@mosaicstack/db';
+import { DB } from '../database/database.module.js';
+import {
+  HierarchyAuditIdempotencyConflictError,
+  HierarchyAuditRepository,
+  HierarchyNodeNotFoundError,
+  type AppendHierarchyEventInput,
+} from './hierarchy-audit.repository.js';
+
+/**
+ * Repository-level §6.4 witnesses for the hierarchy audit machinery
+ * (contract 1 §5.2, REQ-AUD-001): same-transaction atomicity of state +
+ * event + outbox, rollback leaving no residue, idempotent replay, snapshot
+ * parent chains, events surviving target deletion, per-target ordering, and
+ * the outbox claim/complete/release CAS. The schema-level constraints are
+ * witnessed in packages/db/src/hierarchy-audit.witness.test.ts.
+ */
+describe('hierarchy audit repository integration', (): void => {
+  let dataDir: string;
+  let handle: DbHandle;
+  let moduleRef: TestingModule;
+  let repo: HierarchyAuditRepository;
+
+  const input = (
+    overrides: Partial<AppendHierarchyEventInput> = {},
+  ): AppendHierarchyEventInput => ({
+    actorId: 'user-actor',
+    verb: 'create',
+    targetKind: 'company',
+    targetId: randomUUID(),
+    targetSnapshot: { id: 'x', slug: 'x', name: 'x', parentChain: [] },
+    correlationId: 'corr-1',
+    idempotencyKey: `key-${randomUUID()}`,
+    ...overrides,
+  });
+
+  beforeAll(async (): Promise<void> => {
+    dataDir = await mkdtemp(join(tmpdir(), 'mosaic-gateway-hierarchy-audit-'));
+    handle = createPgliteDb(dataDir);
+    await runPgliteMigrations(handle);
+    moduleRef = await Test.createTestingModule({
+      providers: [HierarchyAuditRepository, { provide: DB, useValue: handle.db }],
+    }).compile();
+    repo = moduleRef.get(HierarchyAuditRepository);
+  });
+
+  afterAll(async (): Promise<void> => {
+    await moduleRef.close();
+    await handle.close();
+    await rm(dataDir, { recursive: true, force: true });
+  });
+
+  it('commits state, event, and outbox record atomically in one transaction', async () => {
+    const companyId = randomUUID();
+    const key = `key-${randomUUID()}`;
+    await handle.db.transaction(async (tx) => {
+      await tx.insert(companies).values({ id: companyId, name: 'Atomic Co', slug: 'atomic-co' });
+      const snapshot = await repo.snapshot(tx, 'company', companyId);
+      const result = await repo.append(tx, {
+        ...input({ targetId: companyId, idempotencyKey: key }),
+        targetSnapshot: { ...snapshot },
+      });
+      expect(result.replayed).toBe(false);
+      expect(result.event.idempotencyKey).toBe(key);
+    });
+    const events = await handle.db
+      .select()
+      .from(hierarchyAuditEvents)
+      .where(eq(hierarchyAuditEvents.idempotencyKey, key));
+    expect(events).toHaveLength(1);
+    const outbox = await handle.db
+      .select()
+      .from(hierarchyOutbox)
+      .where(eq(hierarchyOutbox.eventId, events[0]!.id));
+    expect(outbox).toHaveLength(1);
+    expect(outbox[0]).toMatchObject({
+      status: 'pending',
+      idempotencyKey: key,
+      correlationId: 'corr-1',
+    });
+  });
+
+  it('a rolled-back transaction leaves no state, no event, and no outbox record', async () => {
+    const companyId = randomUUID();
+    const key = `key-${randomUUID()}`;
+    await expect(
+      handle.db.transaction(async (tx) => {
+        await tx.insert(companies).values({ id: companyId, name: 'Doomed Co', slug: 'doomed-co' });
+        await repo.append(tx, input({ targetId: companyId, idempotencyKey: key }));
+        throw new Error('deliberate rollback');
+      }),
+    ).rejects.toThrow('deliberate rollback');
+    const [companyRows, eventRows, outboxRows] = await Promise.all([
+      handle.db.select().from(companies).where(eq(companies.id, companyId)),
+      handle.db
+        .select()
+        .from(hierarchyAuditEvents)
+        .where(eq(hierarchyAuditEvents.idempotencyKey, key)),
+      handle.db.select().from(hierarchyOutbox).where(eq(hierarchyOutbox.idempotencyKey, key)),
+    ]);
+    expect(companyRows).toHaveLength(0);
+    expect(eventRows).toHaveLength(0);
+    expect(outboxRows).toHaveLength(0);
+  });
+
+  it('replays a duplicate idempotency key without inserting a second event or outbox record', async () => {
+    const first = input();
+    const original = await handle.db.transaction(async (tx) => repo.append(tx, first));
+    const replay = await handle.db.transaction(async (tx) => repo.append(tx, first));
+    expect(original.replayed).toBe(false);
+    expect(replay.replayed).toBe(true);
+    expect(replay.event.id).toBe(original.event.id);
+    const outbox = await handle.db
+      .select()
+      .from(hierarchyOutbox)
+      .where(eq(hierarchyOutbox.eventId, original.event.id));
+    expect(outbox).toHaveLength(1);
+  });
+
+  it('throws on a duplicate idempotency key carrying different event content', async () => {
+    const first = input();
+    await handle.db.transaction(async (tx) => repo.append(tx, first));
+    await expect(
+      handle.db.transaction(async (tx) =>
+        repo.append(tx, { ...first, verb: 'rename', targetId: randomUUID() }),
+      ),
+    ).rejects.toThrow(HierarchyAuditIdempotencyConflictError);
+  });
+
+  it('throws on a duplicate idempotency key whose transfer destination differs', async () => {
+    const from = { kind: 'company' as const, id: randomUUID(), slug: 'src-co' };
+    const to = { kind: 'company' as const, id: randomUUID(), slug: 'dst-co' };
+    const first = input({
+      verb: 'transfer',
+      targetKind: 'estate',
+      transferFrom: from,
+      transferTo: to,
+    });
+    const original = await handle.db.transaction(async (tx) => repo.append(tx, first));
+    expect(original.replayed).toBe(false);
+    // Identical retry replays; a retry re-routed to a different destination must conflict.
+    const replay = await handle.db.transaction(async (tx) => repo.append(tx, first));
+    expect(replay.replayed).toBe(true);
+    await expect(
+      handle.db.transaction(async (tx) =>
+        repo.append(tx, { ...first, transferTo: { ...to, id: randomUUID() } }),
+      ),
+    ).rejects.toThrow(HierarchyAuditIdempotencyConflictError);
+  });
+
+  it('builds root-first parent chains and rejects unknown nodes', async () => {
+    const companyId = randomUUID();
+    const estateId = randomUUID();
+    const projectId = randomUUID();
+    await handle.db.transaction(async (tx) => {
+      await tx.insert(companies).values({ id: companyId, name: 'Chain Co', slug: 'chain-co' });
+      await tx
+        .insert(estates)
+        .values({ id: estateId, name: 'Chain Estate', slug: 'chain-estate', companyId });
+      await tx
+        .insert(platformProjects)
+        .values({ id: projectId, name: 'Chain Project', slug: 'chain-project', estateId });
+    });
+    const snapshot = await repo.snapshot(handle.db, 'platform_project', projectId);
+    expect(snapshot).toMatchObject({ id: projectId, slug: 'chain-project', name: 'Chain Project' });
+    expect(snapshot.parentChain).toEqual([
+      { kind: 'company', id: companyId, slug: 'chain-co' },
+      { kind: 'estate', id: estateId, slug: 'chain-estate' },
+    ]);
+    await expect(repo.snapshot(handle.db, 'estate', randomUUID())).rejects.toThrow(
+      HierarchyNodeNotFoundError,
+    );
+  });
+
+  it('keeps events readable, in per-target seq order, after the target row is deleted', async () => {
+    const companyId = randomUUID();
+    await handle.db.transaction(async (tx) => {
+      await tx.insert(companies).values({ id: companyId, name: 'Mortal Co', slug: 'mortal-co' });
+      const snapshot = await repo.snapshot(tx, 'company', companyId);
+      await repo.append(tx, input({ targetId: companyId, targetSnapshot: { ...snapshot } }));
+    });
+    await handle.db.transaction(async (tx) => {
+      const snapshot = await repo.snapshot(tx, 'company', companyId);
+      await repo.append(tx, {
+        ...input({ verb: 'delete', targetId: companyId }),
+        targetSnapshot: { ...snapshot },
+      });
+      await tx.delete(companies).where(eq(companies.id, companyId));
+    });
+    const events = await repo.eventsForTarget(companyId);
+    expect(events.map((e) => e.verb)).toEqual(['create', 'delete']);
+    expect(events[1]!.seq).toBeGreaterThan(events[0]!.seq);
+    expect((events[1]!.targetSnapshot as { id: string }).id).toBe(companyId);
+  });
+
+  it('claims the oldest pending outbox record exactly once, completes and releases by CAS', async () => {
+    // Drain records left pending by earlier cases so ordering is deterministic.
+    for (;;) {
+      const drained = await repo.claimPendingOutbox();
+      if (!drained) break;
+      await repo.completeOutbox(drained.id);
+    }
+    const older = await handle.db.transaction(async (tx) => repo.append(tx, input()));
+    const newer = await handle.db.transaction(async (tx) => repo.append(tx, input()));
+
+    const claimed = await repo.claimPendingOutbox();
+    expect(claimed).not.toBeNull();
+    expect(claimed!.eventId).toBe(older.event.id);
+    expect(claimed!.status).toBe('processing');
+
+    // Delivery fails: release returns it to pending and it is claimable again.
+    await repo.releaseOutbox(claimed!.id);
+    const reclaimed = await repo.claimPendingOutbox();
+    expect(reclaimed!.id).toBe(claimed!.id);
+
+    await repo.completeOutbox(reclaimed!.id);
+    const done = await handle.db
+      .select()
+      .from(hierarchyOutbox)
+      .where(eq(hierarchyOutbox.id, reclaimed!.id));
+    expect(done[0]!.status).toBe('delivered');
+    expect(done[0]!.deliveredAt).not.toBeNull();
+    // completeOutbox is CAS-guarded on 'processing': completing again is a no-op.
+    await repo.completeOutbox(reclaimed!.id);
+
+    const second = await repo.claimPendingOutbox();
+    expect(second!.eventId).toBe(newer.event.id);
+    await repo.completeOutbox(second!.id);
+    expect(await repo.claimPendingOutbox()).toBeNull();
+  });
+});

apps/gateway/src/hierarchy/hierarchy-audit.repository.ts

@@ -0,0 +1,274 @@
+import { Inject, Injectable } from '@nestjs/common';
+import {
+  and,
+  asc,
+  companies,
+  eq,
+  estates,
+  hierarchyAuditEvents,
+  hierarchyOutbox,
+  platformProjects,
+  type Db,
+  type HIERARCHY_AUDIT_TARGET_KINDS,
+  type HIERARCHY_AUDIT_VERBS,
+} from '@mosaicstack/db';
+import { DB } from '../database/database.module.js';
+
+/**
+ * Hierarchy audit event + outbox machinery (contract 1 §5.2).
+ *
+ * Every hierarchy mutation writes its semantic audit event AND the event's
+ * outbox record on the caller's transaction, so state, event, and outbox
+ * commit or roll back together. Events reference their target by an
+ * immutable snapshot (id, slug, parent chain at event time), never by a
+ * foreign key into the class tables — append-only events survive the
+ * deletion of their target. This module exposes no update or delete path
+ * for events: append-only is a property of the code surface, witnessed by
+ * the integration tests.
+ *
+ * This is NOT a class-table writer: it touches only the audit/outbox
+ * tables, so it does not appear on the writer-coverage allowlist. The
+ * hierarchy command repository (HierarchyRepository) is the allowlisted
+ * writer and calls into this on its own transactions.
+ */
+
+export type HierarchyAuditVerb = (typeof HIERARCHY_AUDIT_VERBS)[number];
+export type HierarchyTargetKind = (typeof HIERARCHY_AUDIT_TARGET_KINDS)[number];
+export type HierarchyNodeKind = Exclude<HierarchyTargetKind, 'grant'>;
+
+export interface ParentChainEntry {
+  readonly kind: HierarchyNodeKind;
+  readonly id: string;
+  readonly slug: string;
+}
+
+/** Immutable node snapshot at event time; parentChain is root-first. */
+export interface HierarchyNodeSnapshot {
+  readonly id: string;
+  readonly slug: string;
+  readonly name: string;
+  readonly parentChain: readonly ParentChainEntry[];
+}
+
+export interface AppendHierarchyEventInput {
+  readonly actorId: string;
+  readonly verb: HierarchyAuditVerb;
+  readonly targetKind: HierarchyTargetKind;
+  readonly targetId: string;
+  /** Node events: HierarchyNodeSnapshot. Grant events: subject/target/role snapshot (contract 2 §4.4). */
+  readonly targetSnapshot: Record<string, unknown>;
+  /** Present exactly on transfers (CHECK-enforced): source/destination parent { kind, id, slug }. */
+  readonly transferFrom?: ParentChainEntry;
+  readonly transferTo?: ParentChainEntry;
+  readonly correlationId: string;
+  /** Prior event in the causal chain (e.g. the delete event causing cascaded grant_revoke events). */
+  readonly causationId?: string;
+  readonly idempotencyKey: string;
+}
+
+export type HierarchyAuditEventRow = typeof hierarchyAuditEvents.$inferSelect;
+export type HierarchyOutboxRow = typeof hierarchyOutbox.$inferSelect;
+
+export interface AppendHierarchyEventResult {
+  readonly event: HierarchyAuditEventRow;
+  /** True when the idempotency key had already committed an identical event (REQ-AUD-001 duplicate suppression). */
+  readonly replayed: boolean;
+}
+
+type Tx = Pick<Db, 'insert' | 'select'>;
+
+export class HierarchyAuditIdempotencyConflictError extends Error {
+  constructor(idempotencyKey: string) {
+    super(
+      `hierarchy audit idempotency key ${idempotencyKey} already exists with different event content`,
+    );
+    this.name = 'HierarchyAuditIdempotencyConflictError';
+  }
+}
+
+export class HierarchyNodeNotFoundError extends Error {
+  constructor(kind: HierarchyNodeKind, id: string) {
+    super(`hierarchy node not found: ${kind} ${id}`);
+    this.name = 'HierarchyNodeNotFoundError';
+  }
+}
+
+/**
+ * Append one audit event and its outbox record on the caller's transaction.
+ * A duplicate idempotency key with identical semantic content returns the
+ * prior event (replayed: true) without inserting anything; a duplicate key
+ * with different content throws.
+ */
+export async function appendHierarchyEvent(
+  tx: Tx,
+  input: AppendHierarchyEventInput,
+): Promise<AppendHierarchyEventResult> {
+  const inserted = await tx
+    .insert(hierarchyAuditEvents)
+    .values({
+      actorId: input.actorId,
+      verb: input.verb,
+      targetKind: input.targetKind,
+      targetId: input.targetId,
+      targetSnapshot: input.targetSnapshot,
+      transferFrom: input.transferFrom ?? null,
+      transferTo: input.transferTo ?? null,
+      correlationId: input.correlationId,
+      causationId: input.causationId ?? null,
+      idempotencyKey: input.idempotencyKey,
+    })
+    .onConflictDoNothing()
+    .returning();
+  const event = inserted[0];
+  if (event) {
+    await tx.insert(hierarchyOutbox).values({
+      eventId: event.id,
+      idempotencyKey: input.idempotencyKey,
+      correlationId: input.correlationId,
+    });
+    return { event, replayed: false };
+  }
+
+  const prior = await tx
+    .select()
+    .from(hierarchyAuditEvents)
+    .where(eq(hierarchyAuditEvents.idempotencyKey, input.idempotencyKey))
+    .limit(1);
+  const existing = prior[0];
+  if (!existing || !sameEvent(existing, input)) {
+    throw new HierarchyAuditIdempotencyConflictError(input.idempotencyKey);
+  }
+  // Event and outbox committed atomically the first time, so the outbox
+  // record already exists; a replay inserts nothing.
+  return { event: existing, replayed: true };
+}
+
+/** Key-order-independent serialization: jsonb does not preserve key order. */
+function canonicalJson(value: unknown): string {
+  if (Array.isArray(value)) return `[${value.map(canonicalJson).join(',')}]`;
+  if (value !== null && typeof value === 'object') {
+    const record = value as Record<string, unknown>;
+    const body = Object.keys(record)
+      .sort()
+      .map((key) => `${JSON.stringify(key)}:${canonicalJson(record[key])}`)
+      .join(',');
+    return `{${body}}`;
+  }
+  return JSON.stringify(value);
+}
+
+function sameEvent(row: HierarchyAuditEventRow, input: AppendHierarchyEventInput): boolean {
+  return (
+    row.actorId === input.actorId &&
+    row.verb === input.verb &&
+    row.targetKind === input.targetKind &&
+    row.targetId === input.targetId &&
+    row.correlationId === input.correlationId &&
+    (row.causationId ?? null) === (input.causationId ?? null) &&
+    canonicalJson(row.targetSnapshot) === canonicalJson(input.targetSnapshot) &&
+    // Transfer source/destination are semantic content (§5.2): a retry with a
+    // different destination must conflict, never silently replay.
+    canonicalJson(row.transferFrom ?? null) === canonicalJson(input.transferFrom ?? null) &&
+    canonicalJson(row.transferTo ?? null) === canonicalJson(input.transferTo ?? null)
+  );
+}
+
+/**
+ * Build the immutable snapshot for a node: its row plus the parent chain up
+ * to the company root, root-first, read on the caller's transaction so the
+ * snapshot is consistent with the mutation it audits.
+ */
+export async function buildNodeSnapshot(
+  tx: Tx,
+  kind: HierarchyNodeKind,
+  id: string,
+): Promise<HierarchyNodeSnapshot> {
+  if (kind === 'company') {
+    const rows = await tx.select().from(companies).where(eq(companies.id, id)).limit(1);
+    const row = rows[0];
+    if (!row) throw new HierarchyNodeNotFoundError(kind, id);
+    return { id: row.id, slug: row.slug, name: row.name, parentChain: [] };
+  }
+  if (kind === 'estate') {
+    const rows = await tx.select().from(estates).where(eq(estates.id, id)).limit(1);
+    const row = rows[0];
+    if (!row) throw new HierarchyNodeNotFoundError(kind, id);
+    const parent = await buildNodeSnapshot(tx, 'company', row.companyId);
+    return {
+      id: row.id,
+      slug: row.slug,
+      name: row.name,
+      parentChain: [...parent.parentChain, { kind: 'company', id: parent.id, slug: parent.slug }],
+    };
+  }
+  const rows = await tx.select().from(platformProjects).where(eq(platformProjects.id, id)).limit(1);
+  const row = rows[0];
+  if (!row) throw new HierarchyNodeNotFoundError(kind, id);
+  const parent = await buildNodeSnapshot(tx, 'estate', row.estateId);
+  return {
+    id: row.id,
+    slug: row.slug,
+    name: row.name,
+    parentChain: [...parent.parentChain, { kind: 'estate', id: parent.id, slug: parent.slug }],
+  };
+}
+
+@Injectable()
+export class HierarchyAuditRepository {
+  constructor(@Inject(DB) private readonly db: Db) {}
+
+  /** Compose an event+outbox append into a caller-owned transaction. */
+  append(tx: Tx, input: AppendHierarchyEventInput): Promise<AppendHierarchyEventResult> {
+    return appendHierarchyEvent(tx, input);
+  }
+
+  snapshot(tx: Tx, kind: HierarchyNodeKind, id: string): Promise<HierarchyNodeSnapshot> {
+    return buildNodeSnapshot(tx, kind, id);
+  }
+
+  /** Per-target ordered event history (REQ-AUD-001 per-target ordering; read-only). */
+  async eventsForTarget(targetId: string): Promise<HierarchyAuditEventRow[]> {
+    return this.db
+      .select()
+      .from(hierarchyAuditEvents)
+      .where(eq(hierarchyAuditEvents.targetId, targetId))
+      .orderBy(asc(hierarchyAuditEvents.seq));
+  }
+
+  /**
+   * Claim the oldest pending outbox record (claim-by-CAS: the UPDATE is
+   * guarded on status so a lost race returns null and the caller retries).
+   */
+  async claimPendingOutbox(): Promise<HierarchyOutboxRow | null> {
+    const candidates = await this.db
+      .select()
+      .from(hierarchyOutbox)
+      .where(eq(hierarchyOutbox.status, 'pending'))
+      .orderBy(asc(hierarchyOutbox.createdAt))
+      .limit(1);
+    const candidate = candidates[0];
+    if (!candidate) return null;
+    const claimed = await this.db
+      .update(hierarchyOutbox)
+      .set({ status: 'processing', updatedAt: new Date() })
+      .where(and(eq(hierarchyOutbox.id, candidate.id), eq(hierarchyOutbox.status, 'pending')))
+      .returning();
+    return claimed[0] ?? null;
+  }
+
+  async completeOutbox(id: string): Promise<void> {
+    const now = new Date();
+    await this.db
+      .update(hierarchyOutbox)
+      .set({ status: 'delivered', deliveredAt: now, updatedAt: now })
+      .where(and(eq(hierarchyOutbox.id, id), eq(hierarchyOutbox.status, 'processing')));
+  }
+
+  /** Return a claimed record to pending (delivery failed; it stays replayable). */
+  async releaseOutbox(id: string): Promise<void> {
+    await this.db
+      .update(hierarchyOutbox)
+      .set({ status: 'pending', updatedAt: new Date() })
+      .where(and(eq(hierarchyOutbox.id, id), eq(hierarchyOutbox.status, 'processing')));
+  }
+}

apps/gateway/src/hierarchy/hierarchy-commands.integration.test.ts

@@ -0,0 +1,965 @@
+import { mkdtemp, rm } from 'node:fs/promises';
+import { randomUUID } from 'node:crypto';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { Test, type TestingModule } from '@nestjs/testing';
+import {
+  companies,
+  createPgliteDb,
+  eq,
+  estates,
+  hierarchyAuditEvents,
+  hierarchyGrants,
+  hierarchyOutbox,
+  runPgliteMigrations,
+  teams,
+  users,
+  workspaces,
+  type DbHandle,
+} from '@mosaicstack/db';
+import { DB } from '../database/database.module.js';
+import { appendHierarchyEvent } from './hierarchy-audit.repository.js';
+import { HierarchyGrantEvaluationService } from './hierarchy-grant-evaluation.js';
+import { HierarchyRepository, type HierarchyResult } from './hierarchy.repository.js';
+
+/**
+ * Command-level witnesses for the hierarchy command family (M4-1b-ii):
+ * contract 1 §6.4 (per-mutation-class commit + rollback), §6.5
+ * (authorization outcomes), §6.7 (no existence oracle), §6.9 (visibility),
+ * and contract 2 §3 grant-evaluation semantics (deny-by-default,
+ * ancestor-chain inheritance, max-role, live revocation, suspended team
+ * subjects). Schema-level constraints are witnessed in
+ * packages/db/src/hierarchy-schema.witness.test.ts; the audit machinery's
+ * own atomicity in hierarchy-audit.integration.test.ts.
+ *
+ * The rollback legs pre-seed an audit event under the command's idempotency
+ * key with different content: the command's append then throws inside the
+ * command transaction, so the whole mutation must roll back — the command
+ * returns `conflict` and leaves no state change, no second event, and no
+ * second outbox record.
+ */
+describe('hierarchy commands integration', (): void => {
+  let dataDir: string;
+  let handle: DbHandle;
+  let moduleRef: TestingModule;
+  let repo: HierarchyRepository;
+  let evaluation: HierarchyGrantEvaluationService;
+
+  const OWNER = 'hier-cmd-owner';
+  const ADMIN = 'hier-cmd-admin';
+  const STRANGER = 'hier-cmd-stranger';
+  const SUBJECT = 'hier-cmd-subject';
+
+  /** Base fixture: OWNER's company (created through the command surface). */
+  let companyId: string;
+
+  const slug = (prefix: string): string => `${prefix}-${randomUUID().slice(0, 8)}`;
+
+  function expectOk<T>(result: HierarchyResult<T>): { ok: true } & T {
+    if (!result.ok) throw new Error(`expected ok, got ${JSON.stringify(result)}`);
+    return result;
+  }
+
+  const eventsForKey = (key: string) =>
+    handle.db
+      .select()
+      .from(hierarchyAuditEvents)
+      .where(eq(hierarchyAuditEvents.idempotencyKey, key));
+
+  const outboxForKey = (key: string) =>
+    handle.db.select().from(hierarchyOutbox).where(eq(hierarchyOutbox.idempotencyKey, key));
+
+  /** Occupy `key` with unrelated event content so a command reusing it must abort. */
+  const seedConflictingKey = async (key: string): Promise<void> => {
+    await handle.db.transaction(async (tx) =>
+      appendHierarchyEvent(tx, {
+        actorId: 'seed-actor',
+        verb: 'create',
+        targetKind: 'company',
+        targetId: randomUUID(),
+        targetSnapshot: { seeded: true },
+        correlationId: 'seed-correlation',
+        idempotencyKey: key,
+      }),
+    );
+  };
+
+  /**
+   * §6.4 rollback leg: the command must return `conflict` and leave exactly
+   * the seeded event/outbox pair under the key — nothing it wrote survives.
+   */
+  const expectRolledBack = async <T>(
+    key: string,
+    command: () => Promise<HierarchyResult<T>>,
+    assertUnchanged: () => Promise<void>,
+  ): Promise<void> => {
+    await seedConflictingKey(key);
+    const result = await command();
+    expect(result.ok).toBe(false);
+    if (!result.ok) expect(result.error).toBe('conflict');
+    expect(await eventsForKey(key)).toHaveLength(1);
+    expect(await outboxForKey(key)).toHaveLength(1);
+    await assertUnchanged();
+  };
+
+  beforeAll(async (): Promise<void> => {
+    dataDir = await mkdtemp(join(tmpdir(), 'mosaic-gateway-hierarchy-commands-'));
+    handle = createPgliteDb(dataDir);
+    await runPgliteMigrations(handle);
+    moduleRef = await Test.createTestingModule({
+      providers: [
+        HierarchyRepository,
+        HierarchyGrantEvaluationService,
+        { provide: DB, useValue: handle.db },
+      ],
+    }).compile();
+    repo = moduleRef.get(HierarchyRepository);
+    evaluation = moduleRef.get(HierarchyGrantEvaluationService);
+
+    await handle.db.insert(users).values([
+      { id: OWNER, name: 'Owner', email: `${OWNER}@example.com` },
+      { id: ADMIN, name: 'Admin', email: `${ADMIN}@example.com`, role: 'admin' },
+      { id: STRANGER, name: 'Stranger', email: `${STRANGER}@example.com` },
+      { id: SUBJECT, name: 'Subject', email: `${SUBJECT}@example.com` },
+    ]);
+    const created = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Base Co', slug: slug('base') }),
+    );
+    companyId = created.company.id;
+  });
+
+  afterAll(async (): Promise<void> => {
+    await moduleRef.close();
+    await handle.close();
+    await rm(dataDir, { recursive: true, force: true });
+  });
+
+  // ── §6.4 commit legs ───────────────────────────────────────────────────────
+
+  it('createCompany commits company, owner grant, causation-linked events, and outbox atomically', async () => {
+    const key = `key-${randomUUID()}`;
+    const result = expectOk(
+      await repo.createCompany({
+        actorId: OWNER,
+        name: 'Atomic Co',
+        slug: slug('atomic'),
+        idempotencyKey: key,
+      }),
+    );
+    expect(result.company.visibility).toBe('private');
+    expect(result.grant.role).toBe('hierarchy:owner');
+    expect(result.grant.userId).toBe(OWNER);
+    expect(result.grant.grantedBy).toBe(OWNER);
+
+    const [createEvents, grantEvents] = await Promise.all([
+      eventsForKey(key),
+      eventsForKey(`${key}:grant`),
+    ]);
+    expect(createEvents).toHaveLength(1);
+    expect(createEvents[0]).toMatchObject({ verb: 'create', targetId: result.company.id });
+    expect(grantEvents).toHaveLength(1);
+    expect(grantEvents[0]).toMatchObject({ verb: 'grant_create', targetId: result.grant.id });
+    // The grant event is caused by the create event, same correlation (§4.3).
+    expect(grantEvents[0]!.causationId).toBe(createEvents[0]!.id);
+    expect(grantEvents[0]!.correlationId).toBe(createEvents[0]!.correlationId);
+    expect(await outboxForKey(key)).toHaveLength(1);
+    expect(await outboxForKey(`${key}:grant`)).toHaveLength(1);
+
+    const rows = await handle.db
+      .select()
+      .from(companies)
+      .where(eq(companies.id, result.company.id));
+    expect(rows).toHaveLength(1);
+  });
+
+  it('deleteCompany commits the delete with one audited grant_revoke per cascaded grant', async () => {
+    const created = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Mortal Co', slug: slug('mortal') }),
+    );
+    const extraGrant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: created.company.id,
+        role: 'viewer',
+      }),
+    );
+    const key = `key-${randomUUID()}`;
+    expectOk(
+      await repo.deleteCompany({
+        actorId: OWNER,
+        companyId: created.company.id,
+        idempotencyKey: key,
+      }),
+    );
+    const deleteEvents = await eventsForKey(key);
+    expect(deleteEvents).toHaveLength(1);
+    expect(deleteEvents[0]).toMatchObject({ verb: 'delete', targetId: created.company.id });
+    for (const grantId of [created.grant.id, extraGrant.grant.id]) {
+      const revokeEvents = await eventsForKey(`${key}:revoke:${grantId}`);
+      expect(revokeEvents).toHaveLength(1);
+      expect(revokeEvents[0]).toMatchObject({ verb: 'grant_revoke', targetId: grantId });
+      expect(revokeEvents[0]!.causationId).toBe(deleteEvents[0]!.id);
+    }
+    expect(
+      await handle.db.select().from(companies).where(eq(companies.id, created.company.id)),
+    ).toHaveLength(0);
+  });
+
+  // ── §6.4 rollback legs (one per mutation class) ────────────────────────────
+
+  it('renameCompany commits the rename with an audited event carrying previousName', async () => {
+    const created = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Old Name Co', slug: slug('rename') }),
+    );
+    const key = `key-${randomUUID()}`;
+    const renamed = expectOk(
+      await repo.renameCompany({
+        actorId: OWNER,
+        companyId: created.company.id,
+        name: 'New Name Co',
+        idempotencyKey: key,
+      }),
+    );
+    expect(renamed.company.name).toBe('New Name Co');
+
+    const events = await eventsForKey(key);
+    expect(events).toHaveLength(1);
+    expect(events[0]).toMatchObject({ verb: 'rename', targetId: created.company.id });
+    // §6.4: the audited rename carries the old and new names.
+    expect(events[0]!.targetSnapshot).toMatchObject({
+      name: 'New Name Co',
+      previousName: 'Old Name Co',
+    });
+    expect(await outboxForKey(key)).toHaveLength(1);
+
+    const rows = await handle.db
+      .select()
+      .from(companies)
+      .where(eq(companies.id, created.company.id));
+    expect(rows[0]!.name).toBe('New Name Co');
+  });
+
+  it('revokeGrant commits the row deletion with one audited grant_revoke event', async () => {
+    const grant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: companyId,
+        role: 'viewer',
+      }),
+    );
+    const key = `key-${randomUUID()}`;
+    const revoked = expectOk(
+      await repo.revokeGrant({ actorId: OWNER, grantId: grant.grant.id, idempotencyKey: key }),
+    );
+    expect(revoked.revokedId).toBe(grant.grant.id);
+
+    const events = await eventsForKey(key);
+    expect(events).toHaveLength(1);
+    expect(events[0]).toMatchObject({ verb: 'grant_revoke', targetId: grant.grant.id });
+    expect(await outboxForKey(key)).toHaveLength(1);
+
+    // §6 revocation = row deletion: the grant row is gone.
+    const rows = await handle.db
+      .select()
+      .from(hierarchyGrants)
+      .where(eq(hierarchyGrants.id, grant.grant.id));
+    expect(rows).toHaveLength(0);
+  });
+
+  it('rolls back a create: no estate row survives the aborted transaction', async () => {
+    const estateSlug = slug('rb-create');
+    const key = `key-${randomUUID()}`;
+    await expectRolledBack(
+      key,
+      () =>
+        repo.createEstate({
+          actorId: OWNER,
+          companyId,
+          name: 'Doomed Estate',
+          slug: estateSlug,
+          idempotencyKey: key,
+        }),
+      async () => {
+        expect(
+          await handle.db.select().from(estates).where(eq(estates.slug, estateSlug)),
+        ).toHaveLength(0);
+      },
+    );
+  });
+
+  it('rolls back a rename: the company keeps its name', async () => {
+    const before = (
+      await handle.db.select().from(companies).where(eq(companies.id, companyId))
+    )[0]!;
+    const key = `key-${randomUUID()}`;
+    await expectRolledBack(
+      key,
+      () => repo.renameCompany({ actorId: OWNER, companyId, name: 'Never', idempotencyKey: key }),
+      async () => {
+        const after = (
+          await handle.db.select().from(companies).where(eq(companies.id, companyId))
+        )[0]!;
+        expect(after.name).toBe(before.name);
+      },
+    );
+  });
+
+  it('rolls back a visibility change: the company stays private', async () => {
+    const key = `key-${randomUUID()}`;
+    await expectRolledBack(
+      key,
+      () =>
+        repo.changeCompanyVisibility({
+          actorId: ADMIN,
+          companyId,
+          visibility: 'directory',
+          idempotencyKey: key,
+        }),
+      async () => {
+        const after = (
+          await handle.db.select().from(companies).where(eq(companies.id, companyId))
+        )[0]!;
+        expect(after.visibility).toBe('private');
+      },
+    );
+  });
+
+  it('rolls back a transfer: the estate keeps its parent', async () => {
+    const estate = expectOk(
+      await repo.createEstate({ actorId: OWNER, companyId, name: 'RB-T', slug: slug('rb-t') }),
+    );
+    const other = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'RB Dest', slug: slug('rb-dest') }),
+    );
+    const key = `key-${randomUUID()}`;
+    await expectRolledBack(
+      key,
+      () =>
+        repo.transferEstate({
+          actorId: OWNER,
+          estateId: estate.estate.id,
+          destinationCompanyId: other.company.id,
+          idempotencyKey: key,
+        }),
+      async () => {
+        const after = (
+          await handle.db.select().from(estates).where(eq(estates.id, estate.estate.id))
+        )[0]!;
+        expect(after.companyId).toBe(companyId);
+      },
+    );
+  });
+
+  it('rolls back a delete: the estate row survives', async () => {
+    const estate = expectOk(
+      await repo.createEstate({ actorId: OWNER, companyId, name: 'RB-D', slug: slug('rb-d') }),
+    );
+    const key = `key-${randomUUID()}`;
+    await expectRolledBack(
+      key,
+      () => repo.deleteEstate({ actorId: OWNER, estateId: estate.estate.id, idempotencyKey: key }),
+      async () => {
+        expect(
+          await handle.db.select().from(estates).where(eq(estates.id, estate.estate.id)),
+        ).toHaveLength(1);
+      },
+    );
+  });
+
+  it('rolls back a grant create: no grant row survives', async () => {
+    const key = `key-${randomUUID()}`;
+    await expectRolledBack(
+      key,
+      () =>
+        repo.createGrant({
+          actorId: OWNER,
+          userId: STRANGER,
+          targetKind: 'company',
+          targetId: companyId,
+          role: 'viewer',
+          idempotencyKey: key,
+        }),
+      async () => {
+        const rows = await handle.db
+          .select()
+          .from(hierarchyGrants)
+          .where(eq(hierarchyGrants.userId, STRANGER));
+        expect(rows.filter((r) => r.companyId === companyId)).toHaveLength(0);
+      },
+    );
+  });
+
+  it('rolls back a grant change and a grant revoke: the grant keeps its role and its row', async () => {
+    const grant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: companyId,
+        role: 'viewer',
+      }),
+    );
+    const changeKey = `key-${randomUUID()}`;
+    await expectRolledBack(
+      changeKey,
+      () =>
+        repo.changeGrant({
+          actorId: OWNER,
+          grantId: grant.grant.id,
+          role: 'member',
+          idempotencyKey: changeKey,
+        }),
+      async () => {
+        const row = (
+          await handle.db
+            .select()
+            .from(hierarchyGrants)
+            .where(eq(hierarchyGrants.id, grant.grant.id))
+        )[0]!;
+        expect(row.role).toBe('viewer');
+      },
+    );
+    const revokeKey = `key-${randomUUID()}`;
+    await expectRolledBack(
+      revokeKey,
+      () =>
+        repo.revokeGrant({ actorId: OWNER, grantId: grant.grant.id, idempotencyKey: revokeKey }),
+      async () => {
+        expect(
+          await handle.db
+            .select()
+            .from(hierarchyGrants)
+            .where(eq(hierarchyGrants.id, grant.grant.id)),
+        ).toHaveLength(1);
+      },
+    );
+    expectOk(await repo.revokeGrant({ actorId: OWNER, grantId: grant.grant.id }));
+  });
+
+  it('replays a completed command idempotently through the audit machinery', async () => {
+    const key = `key-${randomUUID()}`;
+    const input = { actorId: OWNER, companyId, name: 'Replayed Estate', slug: slug('replay') };
+    const first = expectOk(await repo.createEstate({ ...input, idempotencyKey: key }));
+    // The retry's insert no-ops on the slug conflict — the command surfaces
+    // `conflict`, and crucially appends no second event under the key.
+    const retry = await repo.createEstate({ ...input, idempotencyKey: key });
+    expect(retry.ok).toBe(false);
+    expect(await eventsForKey(key)).toHaveLength(1);
+    expectOk(await repo.deleteEstate({ actorId: OWNER, estateId: first.estate.id }));
+  });
+
+  // ── §6.5 authorization ─────────────────────────────────────────────────────
+
+  it('deny-by-default: a user with no grant cannot mutate and sees not_found (§3.1)', async () => {
+    expect(await repo.renameCompany({ actorId: STRANGER, companyId, name: 'x' })).toEqual({
+      ok: false,
+      error: 'not_found',
+    });
+    expect(
+      await repo.createEstate({ actorId: STRANGER, companyId, name: 'x', slug: slug('deny') }),
+    ).toEqual({ ok: false, error: 'not_found' });
+    expect(await repo.deleteCompany({ actorId: STRANGER, companyId })).toEqual({
+      ok: false,
+      error: 'not_found',
+    });
+  });
+
+  it('grant management requires effective owner: member and viewer are refused (§4.1)', async () => {
+    const grant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: companyId,
+        role: 'member',
+      }),
+    );
+    expect(
+      await repo.createGrant({
+        actorId: SUBJECT,
+        userId: STRANGER,
+        targetKind: 'company',
+        targetId: companyId,
+        role: 'viewer',
+      }),
+    ).toEqual({ ok: false, error: 'not_found' });
+    expect(await repo.revokeGrant({ actorId: SUBJECT, grantId: grant.grant.id })).toEqual({
+      ok: false,
+      error: 'not_found',
+    });
+    // Member also cannot create children (owner-only, §4.1/§4.3).
+    expect(
+      await repo.createEstate({ actorId: SUBJECT, companyId, name: 'x', slug: slug('member') }),
+    ).toEqual({ ok: false, error: 'not_found' });
+    expectOk(await repo.revokeGrant({ actorId: OWNER, grantId: grant.grant.id }));
+  });
+
+  it('platform admin confers no tenant content access (§1.1): ungrated admin is a stranger', async () => {
+    expect(await repo.renameCompany({ actorId: ADMIN, companyId, name: 'x' })).toEqual({
+      ok: false,
+      error: 'not_found',
+    });
+    expect(
+      await repo.createGrant({
+        actorId: ADMIN,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: companyId,
+        role: 'viewer',
+      }),
+    ).toEqual({ ok: false, error: 'not_found' });
+    expect(await repo.listGrantedCompanies(ADMIN)).toEqual([]);
+    expect(await evaluation.effectiveRole(ADMIN, 'company', companyId)).toBeNull();
+  });
+
+  it('visibility change is platform-admin-only (§5.5): the owner is forbidden, the admin succeeds', async () => {
+    const owned = await repo.changeCompanyVisibility({
+      actorId: OWNER,
+      companyId,
+      visibility: 'directory',
+    });
+    expect(owned).toEqual({
+      ok: false,
+      error: 'forbidden',
+      message: 'visibility change is platform-admin-only',
+    });
+    const changed = expectOk(
+      await repo.changeCompanyVisibility({ actorId: ADMIN, companyId, visibility: 'directory' }),
+    );
+    expect(changed.company.visibility).toBe('directory');
+    // Restore for later witnesses.
+    expectOk(
+      await repo.changeCompanyVisibility({ actorId: ADMIN, companyId, visibility: 'private' }),
+    );
+  });
+
+  // ── §6.9 visibility ────────────────────────────────────────────────────────
+
+  it('directory lists exactly directory-class companies with closed fields (§2.8)', async () => {
+    const listed = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Listed Co', slug: slug('listed') }),
+    );
+    const unlisted = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Unlisted Co', slug: slug('unlisted') }),
+    );
+    const key = `key-${randomUUID()}`;
+    expectOk(
+      await repo.changeCompanyVisibility({
+        actorId: ADMIN,
+        companyId: listed.company.id,
+        visibility: 'directory',
+        idempotencyKey: key,
+      }),
+    );
+
+    const directory = await repo.listDirectory();
+    const ids = directory.map((entry) => entry.id);
+    expect(ids).toContain(listed.company.id);
+    expect(ids).not.toContain(unlisted.company.id);
+    expect(ids).not.toContain(companyId);
+    // Closed-field: existence, name, slug — nothing else (no visibility, no
+    // timestamps, no grant or membership data).
+    for (const entry of directory) {
+      expect(Object.keys(entry).sort()).toEqual(['id', 'name', 'slug']);
+    }
+
+    // §5.5: the audited event carries old and new values.
+    const events = await eventsForKey(key);
+    expect(events).toHaveLength(1);
+    expect(events[0]).toMatchObject({ verb: 'visibility_change', targetId: listed.company.id });
+    expect(events[0]!.targetSnapshot).toMatchObject({
+      previousVisibility: 'private',
+      visibility: 'directory',
+    });
+  });
+
+  it('directory disclosure confers no authority: a listed company still refuses non-granted callers (§6.9)', async () => {
+    const listed = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Exposed Co', slug: slug('exposed') }),
+    );
+    expectOk(
+      await repo.changeCompanyVisibility({
+        actorId: ADMIN,
+        companyId: listed.company.id,
+        visibility: 'directory',
+      }),
+    );
+
+    // The company is directory-listed for the whole probe window...
+    expect((await repo.listDirectory()).map((entry) => entry.id)).toContain(listed.company.id);
+
+    // ...but the non-granted reader's granted-read surface still excludes it:
+    // directory disclosure adds existence/name/slug only, never content access.
+    expect(await repo.listGrantedCompanies(STRANGER)).toEqual([]);
+
+    // A stranger mutation of the listed company is refused exactly like a
+    // missing node — the §6.7 carve-out covers the listing, not commands.
+    const realProbe = await repo.renameCompany({
+      actorId: STRANGER,
+      companyId: listed.company.id,
+      name: 'x',
+    });
+    const missingProbe = await repo.renameCompany({
+      actorId: STRANGER,
+      companyId: randomUUID(),
+      name: 'x',
+    });
+    expect(realProbe).toEqual(missingProbe);
+    expect(await repo.deleteCompany({ actorId: STRANGER, companyId: listed.company.id })).toEqual({
+      ok: false,
+      error: 'not_found',
+    });
+  });
+
+  it('granted companies are the reader control: owner sees them, a stranger sees nothing (§2.8)', async () => {
+    const ownerCompanies = await repo.listGrantedCompanies(OWNER);
+    expect(ownerCompanies.map((c) => c.id)).toContain(companyId);
+    expect(await repo.listGrantedCompanies(STRANGER)).toEqual([]);
+  });
+
+  // ── §6.7 no existence oracle ───────────────────────────────────────────────
+
+  it('an unauthorized probe of a real node is indistinguishable from a missing node', async () => {
+    const realCompany = await repo.renameCompany({ actorId: STRANGER, companyId, name: 'x' });
+    const missingCompany = await repo.renameCompany({
+      actorId: STRANGER,
+      companyId: randomUUID(),
+      name: 'x',
+    });
+    expect(realCompany).toEqual(missingCompany);
+
+    const estate = expectOk(
+      await repo.createEstate({
+        actorId: OWNER,
+        companyId,
+        name: 'Oracle E',
+        slug: slug('oracle'),
+      }),
+    );
+    const realEstate = await repo.deleteEstate({ actorId: STRANGER, estateId: estate.estate.id });
+    const missingEstate = await repo.deleteEstate({ actorId: STRANGER, estateId: randomUUID() });
+    expect(realEstate).toEqual(missingEstate);
+
+    const grant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'estate',
+        targetId: estate.estate.id,
+        role: 'viewer',
+      }),
+    );
+    const realGrant = await repo.revokeGrant({ actorId: STRANGER, grantId: grant.grant.id });
+    const missingGrant = await repo.revokeGrant({ actorId: STRANGER, grantId: randomUUID() });
+    expect(realGrant).toEqual(missingGrant);
+    expectOk(await repo.deleteEstate({ actorId: OWNER, estateId: estate.estate.id }));
+  });
+
+  // ── contract 2 §3 grant evaluation ─────────────────────────────────────────
+
+  it('a company grant confers its role down the whole chain, workspace included (§3.2)', async () => {
+    const estate = expectOk(
+      await repo.createEstate({ actorId: OWNER, companyId, name: 'Chain E', slug: slug('chain') }),
+    );
+    const project = expectOk(
+      await repo.createPlatformProject({
+        actorId: OWNER,
+        estateId: estate.estate.id,
+        name: 'Chain P',
+        slug: slug('chain-p'),
+      }),
+    );
+    // Workspaces are evaluable but not hierarchy commands; seed one directly.
+    const workspaceId = randomUUID();
+    await handle.db.insert(workspaces).values({
+      id: workspaceId,
+      name: 'Chain W',
+      slug: slug('chain-w'),
+      platformProjectId: project.platformProject.id,
+    });
+
+    for (const [kind, id] of [
+      ['company', companyId],
+      ['estate', estate.estate.id],
+      ['platform_project', project.platformProject.id],
+      ['workspace', workspaceId],
+    ] as const) {
+      expect(await evaluation.effectiveRole(OWNER, kind, id)).toBe('owner');
+      expect(await evaluation.effectiveRole(STRANGER, kind, id)).toBeNull();
+    }
+
+    // Max-role (§3.3): viewer on the company + owner on the estate → owner at
+    // and below the estate, viewer at the company.
+    const viewerGrant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: companyId,
+        role: 'viewer',
+      }),
+    );
+    const ownerGrant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'estate',
+        targetId: estate.estate.id,
+        role: 'owner',
+      }),
+    );
+    expect(await evaluation.effectiveRole(SUBJECT, 'company', companyId)).toBe('viewer');
+    expect(await evaluation.effectiveRole(SUBJECT, 'estate', estate.estate.id)).toBe('owner');
+    expect(await evaluation.effectiveRole(SUBJECT, 'workspace', workspaceId)).toBe('owner');
+
+    // Revocation is row deletion and denies the very next evaluation (§6).
+    expectOk(await repo.revokeGrant({ actorId: OWNER, grantId: ownerGrant.grant.id }));
+    expect(await evaluation.effectiveRole(SUBJECT, 'estate', estate.estate.id)).toBe('viewer');
+    expectOk(await repo.revokeGrant({ actorId: OWNER, grantId: viewerGrant.grant.id }));
+    expect(await evaluation.effectiveRole(SUBJECT, 'company', companyId)).toBeNull();
+
+    await handle.db.delete(workspaces).where(eq(workspaces.id, workspaceId));
+    expectOk(
+      await repo.deletePlatformProject({
+        actorId: OWNER,
+        platformProjectId: project.platformProject.id,
+      }),
+    );
+    expectOk(await repo.deleteEstate({ actorId: OWNER, estateId: estate.estate.id }));
+  });
+
+  it('team grant subjects are suspended: a team row confers nothing and cannot be changed (§1.4)', async () => {
+    const teamId = randomUUID();
+    await handle.db.insert(teams).values({
+      id: teamId,
+      name: slug('team'),
+      slug: slug('team'),
+      ownerId: SUBJECT,
+      managerId: SUBJECT,
+    });
+    // Out-of-band team row (the command surface cannot create one).
+    const inserted = await handle.db
+      .insert(hierarchyGrants)
+      .values({ teamId, companyId, role: 'owner', grantedBy: OWNER })
+      .returning();
+    const teamGrantId = inserted[0]!.id;
+
+    // The team's own owner gains no effective role from it.
+    expect(await evaluation.effectiveRole(SUBJECT, 'company', companyId)).toBeNull();
+    // changeGrant refuses the row.
+    expect(
+      await repo.changeGrant({ actorId: OWNER, grantId: teamGrantId, role: 'viewer' }),
+    ).toEqual({
+      ok: false,
+      error: 'conflict',
+      message: 'team grant subjects are suspended',
+    });
+    await handle.db.delete(hierarchyGrants).where(eq(hierarchyGrants.id, teamGrantId));
+    await handle.db.delete(teams).where(eq(teams.id, teamId));
+  });
+
+  // ── command conflict semantics ─────────────────────────────────────────────
+
+  it('transfer needs owner on both parents in its own transaction, and refuses no-op and colliding transfers (§5)', async () => {
+    const source = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Src Co', slug: slug('src') }),
+    );
+    const destination = expectOk(
+      await repo.createCompany({ actorId: SUBJECT, name: 'Dst Co', slug: slug('dst') }),
+    );
+    const estateSlug = slug('mv');
+    const estate = expectOk(
+      await repo.createEstate({
+        actorId: OWNER,
+        companyId: source.company.id,
+        name: 'Mv E',
+        slug: estateSlug,
+      }),
+    );
+
+    // OWNER owns the source but not the destination → not_found (§6.7-safe).
+    expect(
+      await repo.transferEstate({
+        actorId: OWNER,
+        estateId: estate.estate.id,
+        destinationCompanyId: destination.company.id,
+      }),
+    ).toEqual({ ok: false, error: 'not_found' });
+
+    // Same-parent transfer is refused.
+    const samePlace = await repo.transferEstate({
+      actorId: OWNER,
+      estateId: estate.estate.id,
+      destinationCompanyId: source.company.id,
+    });
+    expect(samePlace.ok).toBe(false);
+    if (!samePlace.ok) expect(samePlace.error).toBe('conflict');
+
+    // Grant OWNER the destination; a slug collision there is refused.
+    expectOk(
+      await repo.createGrant({
+        actorId: SUBJECT,
+        userId: OWNER,
+        targetKind: 'company',
+        targetId: destination.company.id,
+        role: 'owner',
+      }),
+    );
+    expectOk(
+      await repo.createEstate({
+        actorId: OWNER,
+        companyId: destination.company.id,
+        name: 'Collide',
+        slug: estateSlug,
+      }),
+    );
+    const collision = await repo.transferEstate({
+      actorId: OWNER,
+      estateId: estate.estate.id,
+      destinationCompanyId: destination.company.id,
+    });
+    expect(collision.ok).toBe(false);
+    if (!collision.ok) expect(collision.error).toBe('conflict');
+  });
+
+  it('a successful transfer records transfer_from and transfer_to (§6.4 three-leg witness)', async () => {
+    const from = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'From Co', slug: slug('from') }),
+    );
+    const to = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'To Co', slug: slug('to') }),
+    );
+    const estate = expectOk(
+      await repo.createEstate({
+        actorId: OWNER,
+        companyId: from.company.id,
+        name: 'Moved E',
+        slug: slug('moved'),
+      }),
+    );
+    const key = `key-${randomUUID()}`;
+    expectOk(
+      await repo.transferEstate({
+        actorId: OWNER,
+        estateId: estate.estate.id,
+        destinationCompanyId: to.company.id,
+        idempotencyKey: key,
+      }),
+    );
+    const moved = (
+      await handle.db.select().from(estates).where(eq(estates.id, estate.estate.id))
+    )[0]!;
+    expect(moved.companyId).toBe(to.company.id);
+    const events = await eventsForKey(key);
+    expect(events).toHaveLength(1);
+    expect(events[0]).toMatchObject({ verb: 'transfer', targetId: estate.estate.id });
+    expect(events[0]!.transferFrom).toMatchObject({ kind: 'company', id: from.company.id });
+    expect(events[0]!.transferTo).toMatchObject({ kind: 'company', id: to.company.id });
+    // The post-transfer snapshot's parent chain names the destination.
+    expect(events[0]!.targetSnapshot).toMatchObject({
+      parentChain: [{ kind: 'company', id: to.company.id, slug: to.company.slug }],
+    });
+  });
+
+  it('refuses duplicate slugs, deletes with children, and degenerate grant commands as conflicts', async () => {
+    const co = expectOk(
+      await repo.createCompany({ actorId: OWNER, name: 'Conflict Co', slug: slug('conf') }),
+    );
+    const dupSlug = await repo.createCompany({ actorId: OWNER, name: 'x', slug: co.company.slug });
+    expect(dupSlug.ok).toBe(false);
+    if (!dupSlug.ok) expect(dupSlug.error).toBe('conflict');
+
+    expectOk(
+      await repo.createEstate({
+        actorId: OWNER,
+        companyId: co.company.id,
+        name: 'Child',
+        slug: slug('child'),
+      }),
+    );
+    const withChildren = await repo.deleteCompany({ actorId: OWNER, companyId: co.company.id });
+    expect(withChildren.ok).toBe(false);
+    if (!withChildren.ok) expect(withChildren.error).toBe('conflict');
+
+    // Grant to a nonexistent subject is refused (the caller already holds
+    // owner, so the refusal discloses nothing new).
+    const ghost = await repo.createGrant({
+      actorId: OWNER,
+      userId: `missing-${randomUUID()}`,
+      targetKind: 'company',
+      targetId: co.company.id,
+      role: 'viewer',
+    });
+    expect(ghost.ok).toBe(false);
+    if (!ghost.ok) expect(ghost.error).toBe('conflict');
+
+    const grant = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: co.company.id,
+        role: 'viewer',
+      }),
+    );
+    const duplicate = await repo.createGrant({
+      actorId: OWNER,
+      userId: SUBJECT,
+      targetKind: 'company',
+      targetId: co.company.id,
+      role: 'viewer',
+    });
+    expect(duplicate.ok).toBe(false);
+    if (!duplicate.ok) expect(duplicate.error).toBe('conflict');
+
+    const sameRole = await repo.changeGrant({
+      actorId: OWNER,
+      grantId: grant.grant.id,
+      role: 'viewer',
+    });
+    expect(sameRole.ok).toBe(false);
+    if (!sameRole.ok) expect(sameRole.error).toBe('conflict');
+
+    // A second grant with another role exists → changing the first onto that
+    // role would collide with the unique constraint; refused ahead of it.
+    const second = expectOk(
+      await repo.createGrant({
+        actorId: OWNER,
+        userId: SUBJECT,
+        targetKind: 'company',
+        targetId: co.company.id,
+        role: 'member',
+      }),
+    );
+    const collide = await repo.changeGrant({
+      actorId: OWNER,
+      grantId: grant.grant.id,
+      role: 'member',
+    });
+    expect(collide.ok).toBe(false);
+    if (!collide.ok) expect(collide.error).toBe('conflict');
+
+    // A clean change succeeds and records the previous role, namespaced (§4.5).
+    const changeKey = `key-${randomUUID()}`;
+    const changed = expectOk(
+      await repo.changeGrant({
+        actorId: OWNER,
+        grantId: second.grant.id,
+        role: 'owner',
+        idempotencyKey: changeKey,
+      }),
+    );
+    expect(changed.grant.role).toBe('hierarchy:owner');
+    const events = await eventsForKey(changeKey);
+    expect(events).toHaveLength(1);
+    expect(events[0]!.targetSnapshot).toMatchObject({
+      role: 'hierarchy:owner',
+      previousRole: 'hierarchy:member',
+    });
+  });
+});

apps/gateway/src/hierarchy/hierarchy-grant-evaluation.ts

@@ -0,0 +1,242 @@
+import { Inject, Injectable } from '@nestjs/common';
+import {
+  companies,
+  eq,
+  estates,
+  hierarchyGrants,
+  inArray,
+  or,
+  platformProjects,
+  workspaces,
+  and,
+  type Db,
+  HIERARCHY_GRANT_ROLES,
+} from '@mosaicstack/db';
+import { DB } from '../database/database.module.js';
+
+/**
+ * Hierarchy grant evaluation (contract 2 §3).
+ *
+ * Deny-by-default (§3.1): a user's effective role on a node is null unless a
+ * grant row explicitly confers one. Grants apply down the chain only (§3.2):
+ * the effective role on a node is the maximum role over grants targeting the
+ * node itself or any of its ancestors, maximum per the total order
+ * viewer ⊂ member ⊂ owner (§2). Evaluation is live and per-decision — no
+ * caching — so revocation (row deletion, §6) denies the next decision
+ * inherently. A missing node evaluates to null, indistinguishable from
+ * no-grant, which keeps unauthorized probes oracle-safe (contract 1 §6.7).
+ *
+ * Team grant subjects are SUSPENDED (§1.4): the command surface refuses to
+ * create them and this evaluator considers user-subject grants only, so a
+ * team row could not confer access even if one existed.
+ *
+ * Read-only module: it selects from the class tables but never writes them,
+ * so it does not appear on the writer-coverage allowlist.
+ */
+
+export type HierarchyGrantRole = (typeof HIERARCHY_GRANT_ROLES)[number];
+
+/** Node kinds a grant may target (§3.2; workspace is evaluable, not grantable). */
+export type GrantTargetKind = 'company' | 'estate' | 'platform_project';
+/** Node kinds an authorization decision may be evaluated at (§3.2: down to workspace). */
+export type EvaluableNodeKind = GrantTargetKind | 'workspace';
+
+type Tx = Pick<Db, 'select'>;
+
+/** Ancestor chain of a node, self included at its own level; ids only. */
+export interface AncestorChain {
+  readonly companyId: string;
+  readonly estateId?: string;
+  readonly platformProjectId?: string;
+  readonly workspaceId?: string;
+}
+
+export function roleStrength(role: HierarchyGrantRole): number {
+  return HIERARCHY_GRANT_ROLES.indexOf(role);
+}
+
+export function roleAtLeast(
+  role: HierarchyGrantRole | null,
+  required: HierarchyGrantRole,
+): boolean {
+  return role !== null && roleStrength(role) >= roleStrength(required);
+}
+
+/**
+ * Serialized role strings are namespaced (§4.5): audit events and API
+ * responses carry `hierarchy:owner`, never a bare `owner`.
+ */
+export function namespacedHierarchyRole(role: HierarchyGrantRole): string {
+  return `hierarchy:${role}`;
+}
+
+/**
+ * Resolve a node's ancestor chain (self included). Returns null when the
+ * node does not exist — callers treat that exactly like no-grant (§3.1,
+ * oracle-safe).
+ */
+export async function resolveAncestorChain(
+  tx: Tx,
+  kind: EvaluableNodeKind,
+  id: string,
+): Promise<AncestorChain | null> {
+  if (kind === 'company') {
+    const rows = await tx
+      .select({ id: companies.id })
+      .from(companies)
+      .where(eq(companies.id, id))
+      .limit(1);
+    const row = rows[0];
+    return row ? { companyId: row.id } : null;
+  }
+  if (kind === 'estate') {
+    const rows = await tx
+      .select({ id: estates.id, companyId: estates.companyId })
+      .from(estates)
+      .where(eq(estates.id, id))
+      .limit(1);
+    const row = rows[0];
+    return row ? { companyId: row.companyId, estateId: row.id } : null;
+  }
+  if (kind === 'platform_project') {
+    const rows = await tx
+      .select({
+        id: platformProjects.id,
+        estateId: platformProjects.estateId,
+        companyId: estates.companyId,
+      })
+      .from(platformProjects)
+      .innerJoin(estates, eq(estates.id, platformProjects.estateId))
+      .where(eq(platformProjects.id, id))
+      .limit(1);
+    const row = rows[0];
+    return row
+      ? { companyId: row.companyId, estateId: row.estateId, platformProjectId: row.id }
+      : null;
+  }
+  const rows = await tx
+    .select({
+      id: workspaces.id,
+      platformProjectId: workspaces.platformProjectId,
+      estateId: platformProjects.estateId,
+      companyId: estates.companyId,
+    })
+    .from(workspaces)
+    .innerJoin(platformProjects, eq(platformProjects.id, workspaces.platformProjectId))
+    .innerJoin(estates, eq(estates.id, platformProjects.estateId))
+    .where(eq(workspaces.id, id))
+    .limit(1);
+  const row = rows[0];
+  return row
+    ? {
+        companyId: row.companyId,
+        estateId: row.estateId,
+        platformProjectId: row.platformProjectId,
+        workspaceId: row.id,
+      }
+    : null;
+}
+
+function maxRole(roles: readonly string[]): HierarchyGrantRole | null {
+  let best: HierarchyGrantRole | null = null;
+  for (const candidate of roles) {
+    // Fail-closed: a value outside the vocabulary confers nothing.
+    if (!(HIERARCHY_GRANT_ROLES as readonly string[]).includes(candidate)) continue;
+    const role = candidate as HierarchyGrantRole;
+    if (best === null || roleStrength(role) > roleStrength(best)) best = role;
+  }
+  return best;
+}
+
+/**
+ * Effective role of a user on a node: maximum over the user's grants whose
+ * target is the node or any ancestor (§3.2); null = deny (§3.1). Missing
+ * node → null.
+ */
+export async function evaluateEffectiveRole(
+  tx: Tx,
+  userId: string,
+  kind: EvaluableNodeKind,
+  id: string,
+): Promise<HierarchyGrantRole | null> {
+  const chain = await resolveAncestorChain(tx, kind, id);
+  if (!chain) return null;
+
+  const targetConditions = [eq(hierarchyGrants.companyId, chain.companyId)];
+  if (chain.estateId) targetConditions.push(eq(hierarchyGrants.estateId, chain.estateId));
+  if (chain.platformProjectId) {
+    targetConditions.push(eq(hierarchyGrants.platformProjectId, chain.platformProjectId));
+  }
+
+  const rows = await tx
+    .select({ role: hierarchyGrants.role })
+    .from(hierarchyGrants)
+    .where(and(eq(hierarchyGrants.userId, userId), or(...targetConditions)));
+  return maxRole(rows.map((r) => r.role));
+}
+
+/**
+ * All companies on which the user holds any effective role, i.e. companies
+ * with a grant on the company itself or on any descendant (contract 1 §2.8:
+ * a grant anywhere in the subtree discloses the company's chain upward).
+ */
+export async function grantedCompanyIds(tx: Tx, userId: string): Promise<string[]> {
+  const grants = await tx
+    .select({
+      companyId: hierarchyGrants.companyId,
+      estateId: hierarchyGrants.estateId,
+      platformProjectId: hierarchyGrants.platformProjectId,
+    })
+    .from(hierarchyGrants)
+    .where(eq(hierarchyGrants.userId, userId));
+
+  const companyIds = new Set<string>();
+  const estateIds = new Set<string>();
+  const platformProjectIds = new Set<string>();
+  for (const grant of grants) {
+    if (grant.companyId) companyIds.add(grant.companyId);
+    else if (grant.estateId) estateIds.add(grant.estateId);
+    else if (grant.platformProjectId) platformProjectIds.add(grant.platformProjectId);
+  }
+
+  if (platformProjectIds.size > 0) {
+    const rows = await tx
+      .select({ estateId: platformProjects.estateId })
+      .from(platformProjects)
+      .where(inArray(platformProjects.id, [...platformProjectIds]));
+    for (const row of rows) estateIds.add(row.estateId);
+  }
+  if (estateIds.size > 0) {
+    const rows = await tx
+      .select({ companyId: estates.companyId })
+      .from(estates)
+      .where(inArray(estates.id, [...estateIds]));
+    for (const row of rows) companyIds.add(row.companyId);
+  }
+  return [...companyIds];
+}
+
+@Injectable()
+export class HierarchyGrantEvaluationService {
+  constructor(@Inject(DB) private readonly db: Db) {}
+
+  /** Live per-decision evaluation; pass a tx to evaluate inside a command's transaction. */
+  effectiveRole(
+    userId: string,
+    kind: EvaluableNodeKind,
+    id: string,
+    tx?: Tx,
+  ): Promise<HierarchyGrantRole | null> {
+    return evaluateEffectiveRole(tx ?? this.db, userId, kind, id);
+  }
+
+  async hasRole(
+    userId: string,
+    kind: EvaluableNodeKind,
+    id: string,
+    required: HierarchyGrantRole,
+    tx?: Tx,
+  ): Promise<boolean> {
+    return roleAtLeast(await this.effectiveRole(userId, kind, id, tx), required);
+  }
+}

apps/gateway/src/hierarchy/hierarchy.controller.ts

@@ -0,0 +1,297 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  HttpCode,
+  Param,
+  ParseUUIDPipe,
+  Post,
+  UseGuards,
+} from '@nestjs/common';
+import { AuthGuard } from '../auth/auth.guard.js';
+import { CurrentUser } from '../auth/current-user.decorator.js';
+import {
+  ChangeCompanyVisibilityDto,
+  ChangeGrantDto,
+  CreateCompanyDto,
+  CreateEstateDto,
+  CreateGrantDto,
+  CreatePlatformProjectDto,
+  DeleteNodeDto,
+  RenameNodeDto,
+  TransferEstateDto,
+  TransferPlatformProjectDto,
+} from './hierarchy.dto.js';
+import { HierarchyRepository } from './hierarchy.repository.js';
+import { HierarchyService } from './hierarchy.service.js';
+
+/**
+ * The hierarchy command family (contract 1 §5, §6.3). This controller is the
+ * closed HTTP surface over the hierarchy class tables: the route-inventory
+ * witness asserts these routes and no others exist. Delete commands take an
+ * optional body (idempotency key) via POST-style DTOs; every mutation is
+ * audited on its own transaction by the repository.
+ */
+@Controller('api/hierarchy')
+@UseGuards(AuthGuard)
+export class HierarchyController {
+  constructor(
+    private readonly repository: HierarchyRepository,
+    private readonly service: HierarchyService,
+  ) {}
+
+  // ── companies ────────────────────────────────────────────────────────────
+
+  @Post('companies')
+  async createCompany(@CurrentUser() user: { id: string }, @Body() dto: CreateCompanyDto) {
+    return this.service.unwrap(
+      await this.repository.createCompany({
+        actorId: user.id,
+        name: dto.name,
+        slug: dto.slug,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  /** Companies the caller holds a grant on (directly or via a descendant). */
+  @Get('companies')
+  listGrantedCompanies(@CurrentUser() user: { id: string }) {
+    return this.repository.listGrantedCompanies(user.id);
+  }
+
+  /** Directory-class companies, closed-field (§2.8). */
+  @Get('companies/directory')
+  listDirectory() {
+    return this.repository.listDirectory();
+  }
+
+  @Post('companies/:id/rename')
+  @HttpCode(200)
+  async renameCompany(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: RenameNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.renameCompany({
+        actorId: user.id,
+        companyId: id,
+        name: dto.name,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Post('companies/:id/visibility')
+  @HttpCode(200)
+  async changeCompanyVisibility(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: ChangeCompanyVisibilityDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.changeCompanyVisibility({
+        actorId: user.id,
+        companyId: id,
+        visibility: dto.visibility,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Delete('companies/:id')
+  async deleteCompany(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: DeleteNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.deleteCompany({
+        actorId: user.id,
+        companyId: id,
+        idempotencyKey: dto?.idempotencyKey,
+      }),
+    );
+  }
+
+  // ── estates ──────────────────────────────────────────────────────────────
+
+  @Post('estates')
+  async createEstate(@CurrentUser() user: { id: string }, @Body() dto: CreateEstateDto) {
+    return this.service.unwrap(
+      await this.repository.createEstate({
+        actorId: user.id,
+        companyId: dto.companyId,
+        name: dto.name,
+        slug: dto.slug,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Post('estates/:id/rename')
+  @HttpCode(200)
+  async renameEstate(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: RenameNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.renameEstate({
+        actorId: user.id,
+        estateId: id,
+        name: dto.name,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Post('estates/:id/transfer')
+  @HttpCode(200)
+  async transferEstate(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: TransferEstateDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.transferEstate({
+        actorId: user.id,
+        estateId: id,
+        destinationCompanyId: dto.destinationCompanyId,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Delete('estates/:id')
+  async deleteEstate(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: DeleteNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.deleteEstate({
+        actorId: user.id,
+        estateId: id,
+        idempotencyKey: dto?.idempotencyKey,
+      }),
+    );
+  }
+
+  // ── platform projects ────────────────────────────────────────────────────
+
+  @Post('platform-projects')
+  async createPlatformProject(
+    @CurrentUser() user: { id: string },
+    @Body() dto: CreatePlatformProjectDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.createPlatformProject({
+        actorId: user.id,
+        estateId: dto.estateId,
+        name: dto.name,
+        slug: dto.slug,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Post('platform-projects/:id/rename')
+  @HttpCode(200)
+  async renamePlatformProject(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: RenameNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.renamePlatformProject({
+        actorId: user.id,
+        platformProjectId: id,
+        name: dto.name,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Post('platform-projects/:id/transfer')
+  @HttpCode(200)
+  async transferPlatformProject(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: TransferPlatformProjectDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.transferPlatformProject({
+        actorId: user.id,
+        platformProjectId: id,
+        destinationEstateId: dto.destinationEstateId,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Delete('platform-projects/:id')
+  async deletePlatformProject(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: DeleteNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.deletePlatformProject({
+        actorId: user.id,
+        platformProjectId: id,
+        idempotencyKey: dto?.idempotencyKey,
+      }),
+    );
+  }
+
+  // ── grants ───────────────────────────────────────────────────────────────
+
+  @Post('grants')
+  async createGrant(@CurrentUser() user: { id: string }, @Body() dto: CreateGrantDto) {
+    return this.service.unwrap(
+      await this.repository.createGrant({
+        actorId: user.id,
+        userId: dto.userId,
+        targetKind: dto.targetKind,
+        targetId: dto.targetId,
+        role: dto.role,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Post('grants/:id/change')
+  @HttpCode(200)
+  async changeGrant(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: ChangeGrantDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.changeGrant({
+        actorId: user.id,
+        grantId: id,
+        role: dto.role,
+        idempotencyKey: dto.idempotencyKey,
+      }),
+    );
+  }
+
+  @Delete('grants/:id')
+  async revokeGrant(
+    @CurrentUser() user: { id: string },
+    @Param('id', ParseUUIDPipe) id: string,
+    @Body() dto: DeleteNodeDto,
+  ) {
+    return this.service.unwrap(
+      await this.repository.revokeGrant({
+        actorId: user.id,
+        grantId: id,
+        idempotencyKey: dto?.idempotencyKey,
+      }),
+    );
+  }
+}

apps/gateway/src/hierarchy/hierarchy.dto.ts

@@ -0,0 +1,169 @@
+import { COMPANY_VISIBILITY, HIERARCHY_GRANT_ROLES } from '@mosaicstack/db';
+import { IsIn, IsOptional, IsString, IsUUID, Matches, MaxLength, MinLength } from 'class-validator';
+
+/**
+ * Hierarchy command DTOs (contract 1 §5, contract 2 §4/§7).
+ *
+ * The global ValidationPipe runs with whitelist + forbidNonWhitelisted, so a
+ * payload field absent from these classes is a 400. That closure is itself
+ * contract surface:
+ *  - CreateCompanyDto declares NO visibility field — creation is always
+ *    private (contract 1 §5.5); a visibility argument is refused by the pipe.
+ *  - CreateGrantDto declares NO teamId field — team grant subjects are
+ *    suspended (contract 2 §1.4/§7.5); a team subject is refused by the pipe.
+ * Every class here must be registered in PIPE_GUARDED_DTOS so the boot-time
+ * assertion proves the pipe sees the decorators.
+ */
+
+const SLUG_PATTERN = /^[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/;
+const SLUG_MESSAGE = 'slug must be lowercase alphanumeric with interior hyphens';
+
+export class CreateCompanyDto {
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  name!: string;
+
+  @IsString()
+  @MaxLength(100)
+  @Matches(SLUG_PATTERN, { message: SLUG_MESSAGE })
+  slug!: string;
+
+  /** Client-supplied idempotency key (REQ-AUD-001 replay); server-generated when absent. */
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class RenameNodeDto {
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  name!: string;
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class ChangeCompanyVisibilityDto {
+  @IsIn(COMPANY_VISIBILITY)
+  visibility!: (typeof COMPANY_VISIBILITY)[number];
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class DeleteNodeDto {
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class CreateEstateDto {
+  @IsUUID()
+  companyId!: string;
+
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  name!: string;
+
+  @IsString()
+  @MaxLength(100)
+  @Matches(SLUG_PATTERN, { message: SLUG_MESSAGE })
+  slug!: string;
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class CreatePlatformProjectDto {
+  @IsUUID()
+  estateId!: string;
+
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  name!: string;
+
+  @IsString()
+  @MaxLength(100)
+  @Matches(SLUG_PATTERN, { message: SLUG_MESSAGE })
+  slug!: string;
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class TransferEstateDto {
+  @IsUUID()
+  destinationCompanyId!: string;
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class TransferPlatformProjectDto {
+  @IsUUID()
+  destinationEstateId!: string;
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class CreateGrantDto {
+  /** Subject user (better-auth text id). No teamId field — see module doc. */
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  userId!: string;
+
+  @IsIn(['company', 'estate', 'platform_project'])
+  targetKind!: 'company' | 'estate' | 'platform_project';
+
+  @IsUUID()
+  targetId!: string;
+
+  /** Bare vocabulary on requests; responses and audit events are namespaced (§4.5). */
+  @IsIn(HIERARCHY_GRANT_ROLES)
+  role!: (typeof HIERARCHY_GRANT_ROLES)[number];
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}
+
+export class ChangeGrantDto {
+  @IsIn(HIERARCHY_GRANT_ROLES)
+  role!: (typeof HIERARCHY_GRANT_ROLES)[number];
+
+  @IsOptional()
+  @IsString()
+  @MinLength(1)
+  @MaxLength(255)
+  idempotencyKey?: string;
+}

apps/gateway/src/hierarchy/hierarchy.module.ts

@@ -0,0 +1,28 @@
+import { Module } from '@nestjs/common';
+import { HierarchyAuditRepository } from './hierarchy-audit.repository.js';
+import { HierarchyGrantEvaluationService } from './hierarchy-grant-evaluation.js';
+import { HierarchyController } from './hierarchy.controller.js';
+import { HierarchyRepository } from './hierarchy.repository.js';
+import { HierarchyService } from './hierarchy.service.js';
+
+/**
+ * Hierarchy (tenancy/authorization structure) feature module.
+ *
+ * M4-1b-i shipped the audit event + outbox machinery (contract 1 §5.2);
+ * M4-1b-ii adds the command family — the closed route surface asserted by
+ * the route-inventory witness — plus grant evaluation (contract 2 §3).
+ * HierarchyRepository is the sole class-table writer (writer-coverage
+ * allowlist); every mutation runs authorize → mutate → audit in one
+ * transaction.
+ */
+@Module({
+  controllers: [HierarchyController],
+  providers: [
+    HierarchyAuditRepository,
+    HierarchyGrantEvaluationService,
+    HierarchyRepository,
+    HierarchyService,
+  ],
+  exports: [HierarchyAuditRepository, HierarchyGrantEvaluationService],
+})
+export class HierarchyModule {}

apps/gateway/src/hierarchy/hierarchy.repository.ts

@@ -0,0 +1,935 @@
+import { randomUUID } from 'node:crypto';
+import { Inject, Injectable } from '@nestjs/common';
+import {
+  and,
+  asc,
+  companies,
+  eq,
+  estates,
+  hierarchyGrants,
+  inArray,
+  platformProjects,
+  users,
+  workspaces,
+  type Db,
+} from '@mosaicstack/db';
+import { DB } from '../database/database.module.js';
+import {
+  appendHierarchyEvent,
+  buildNodeSnapshot,
+  HierarchyAuditIdempotencyConflictError,
+} from './hierarchy-audit.repository.js';
+import {
+  evaluateEffectiveRole,
+  grantedCompanyIds,
+  namespacedHierarchyRole,
+  roleAtLeast,
+  type GrantTargetKind,
+  type HierarchyGrantRole,
+} from './hierarchy-grant-evaluation.js';
+
+/**
+ * Hierarchy command repository (contract 1 §5, contract 2 §4).
+ *
+ * The ONLY writer of the hierarchy class tables (companies, estates,
+ * platform_projects, hierarchy_grants) — it is the writer-coverage
+ * allowlist's sole entry. Every command runs one transaction that
+ * authorizes (live grant evaluation inside the same transaction), mutates,
+ * and appends the semantic audit event + outbox record via the M4-1b-i
+ * machinery, so state, event, and outbox commit or roll back together
+ * (REQ-AUD-001).
+ *
+ * Authorization failure and target-not-found both return `not_found`
+ * (contract 1 §6.7: no existence oracle — an unauthorized caller learns
+ * nothing a stranger would not). `forbidden` appears only where the caller
+ * already knows the surface exists independent of any node: the admin-only
+ * visibility change (§5.5). Serialized role strings are namespaced (§4.5).
+ */
+
+export type HierarchyCommandFailure =
+  | { readonly ok: false; readonly error: 'not_found' }
+  | { readonly ok: false; readonly error: 'forbidden'; readonly message: string }
+  | { readonly ok: false; readonly error: 'conflict'; readonly message: string };
+
+export type HierarchyResult<T> = ({ readonly ok: true } & T) | HierarchyCommandFailure;
+
+export interface CompanyView {
+  readonly id: string;
+  readonly name: string;
+  readonly slug: string;
+  readonly visibility: string;
+}
+
+export interface NodeView {
+  readonly id: string;
+  readonly name: string;
+  readonly slug: string;
+}
+
+export interface GrantView {
+  readonly id: string;
+  readonly userId: string;
+  readonly targetKind: GrantTargetKind;
+  readonly targetId: string;
+  /** Namespaced (§4.5), e.g. `hierarchy:owner`. */
+  readonly role: string;
+  readonly grantedBy: string;
+}
+
+/** Directory rows are closed-field: existence, name, slug — nothing else (§2.8). */
+export interface DirectoryEntry {
+  readonly id: string;
+  readonly name: string;
+  readonly slug: string;
+}
+
+type Tx = Pick<Db, 'insert' | 'select' | 'update' | 'delete'>;
+type GrantRow = typeof hierarchyGrants.$inferSelect;
+
+const NOT_FOUND: HierarchyCommandFailure = { ok: false, error: 'not_found' };
+
+function conflict(message: string): HierarchyCommandFailure {
+  return { ok: false, error: 'conflict', message };
+}
+
+function grantTarget(row: GrantRow): { kind: GrantTargetKind; id: string } {
+  if (row.companyId) return { kind: 'company', id: row.companyId };
+  if (row.estateId) return { kind: 'estate', id: row.estateId };
+  return { kind: 'platform_project', id: row.platformProjectId as string };
+}
+
+/** Grant event snapshot (contract 2 §4.4): subject, target, namespaced role, grantor. */
+function grantSnapshot(row: GrantRow): Record<string, unknown> {
+  const target = grantTarget(row);
+  return {
+    id: row.id,
+    subject: { userId: row.userId },
+    target: { kind: target.kind, id: target.id },
+    role: namespacedHierarchyRole(row.role as HierarchyGrantRole),
+    grantedBy: row.grantedBy,
+  };
+}
+
+function grantView(row: GrantRow): GrantView {
+  const target = grantTarget(row);
+  return {
+    id: row.id,
+    userId: row.userId as string,
+    targetKind: target.kind,
+    targetId: target.id,
+    role: namespacedHierarchyRole(row.role as HierarchyGrantRole),
+    grantedBy: row.grantedBy,
+  };
+}
+
+function companyView(row: typeof companies.$inferSelect): CompanyView {
+  return { id: row.id, name: row.name, slug: row.slug, visibility: row.visibility };
+}
+
+interface CommandContext {
+  readonly actorId: string;
+  readonly idempotencyKey: string;
+  readonly correlationId: string;
+}
+
+@Injectable()
+export class HierarchyRepository {
+  constructor(@Inject(DB) private readonly db: Db) {}
+
+  private async run<T>(
+    idempotencyKey: string | undefined,
+    actorId: string,
+    body: (tx: Tx, ctx: CommandContext) => Promise<HierarchyResult<T>>,
+  ): Promise<HierarchyResult<T>> {
+    const ctx: CommandContext = {
+      actorId,
+      idempotencyKey: idempotencyKey ?? randomUUID(),
+      correlationId: randomUUID(),
+    };
+    try {
+      return await this.db.transaction(async (tx) => body(tx, ctx));
+    } catch (error) {
+      // A key replayed with different content aborts the whole command —
+      // the transaction (state change included) has rolled back (§6.4).
+      if (error instanceof HierarchyAuditIdempotencyConflictError) {
+        return conflict(error.message);
+      }
+      throw error;
+    }
+  }
+
+  private async requireOwner(
+    tx: Tx,
+    actorId: string,
+    kind: GrantTargetKind,
+    id: string,
+  ): Promise<boolean> {
+    return roleAtLeast(await evaluateEffectiveRole(tx, actorId, kind, id), 'owner');
+  }
+
+  private async isPlatformAdmin(tx: Tx, actorId: string): Promise<boolean> {
+    const rows = await tx
+      .select({ role: users.role })
+      .from(users)
+      .where(eq(users.id, actorId))
+      .limit(1);
+    return rows[0]?.role === 'admin';
+  }
+
+  // ── companies ────────────────────────────────────────────────────────────
+
+  /**
+   * Any authenticated user may create a company; the same audited operation
+   * writes the creator's initial owner grant (§4.3), causation-linked to the
+   * create event. Visibility is always 'private' — the command takes no
+   * visibility input (§5.5).
+   */
+  createCompany(input: {
+    actorId: string;
+    name: string;
+    slug: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ company: CompanyView; grant: GrantView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      const inserted = await tx
+        .insert(companies)
+        .values({ name: input.name, slug: input.slug })
+        .onConflictDoNothing()
+        .returning();
+      const company = inserted[0];
+      if (!company) return conflict('company slug already exists');
+
+      const grantRows = await tx
+        .insert(hierarchyGrants)
+        .values({
+          userId: ctx.actorId,
+          companyId: company.id,
+          role: 'owner',
+          grantedBy: ctx.actorId,
+        })
+        .returning();
+      const grant = grantRows[0] as GrantRow;
+
+      const snapshot = await buildNodeSnapshot(tx, 'company', company.id);
+      const created = await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'create',
+        targetKind: 'company',
+        targetId: company.id,
+        targetSnapshot: { ...snapshot },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'grant_create',
+        targetKind: 'grant',
+        targetId: grant.id,
+        targetSnapshot: grantSnapshot(grant),
+        correlationId: ctx.correlationId,
+        causationId: created.event.id,
+        idempotencyKey: `${ctx.idempotencyKey}:grant`,
+      });
+      return { ok: true, company: companyView(company), grant: grantView(grant) };
+    });
+  }
+
+  renameCompany(input: {
+    actorId: string;
+    companyId: string;
+    name: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ company: CompanyView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, 'company', input.companyId))) {
+        return NOT_FOUND;
+      }
+      const rows = await tx
+        .select()
+        .from(companies)
+        .where(eq(companies.id, input.companyId))
+        .limit(1);
+      const previous = rows[0];
+      if (!previous) return NOT_FOUND;
+
+      const updated = await tx
+        .update(companies)
+        .set({ name: input.name, updatedAt: new Date() })
+        .where(eq(companies.id, input.companyId))
+        .returning();
+      const company = updated[0] as typeof companies.$inferSelect;
+
+      const snapshot = await buildNodeSnapshot(tx, 'company', company.id);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'rename',
+        targetKind: 'company',
+        targetId: company.id,
+        targetSnapshot: { ...snapshot, previousName: previous.name },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, company: companyView(company) };
+    });
+  }
+
+  /**
+   * Admin-only until the company-CRUD capability ratifies (§5.5) — the one
+   * hierarchy mutation a platform admin performs without a grant. A
+   * non-admin caller (owner included) gets `forbidden` before any company
+   * read: the refusal reveals nothing about the target's existence.
+   */
+  changeCompanyVisibility(input: {
+    actorId: string;
+    companyId: string;
+    visibility: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ company: CompanyView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.isPlatformAdmin(tx, ctx.actorId))) {
+        return {
+          ok: false,
+          error: 'forbidden',
+          message: 'visibility change is platform-admin-only',
+        };
+      }
+      const rows = await tx
+        .select()
+        .from(companies)
+        .where(eq(companies.id, input.companyId))
+        .limit(1);
+      const previous = rows[0];
+      if (!previous) return NOT_FOUND;
+
+      const updated = await tx
+        .update(companies)
+        .set({ visibility: input.visibility, updatedAt: new Date() })
+        .where(eq(companies.id, input.companyId))
+        .returning();
+      const company = updated[0] as typeof companies.$inferSelect;
+
+      const snapshot = await buildNodeSnapshot(tx, 'company', company.id);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'visibility_change',
+        targetKind: 'company',
+        targetId: company.id,
+        // Old and new values are event content (§5.5).
+        targetSnapshot: {
+          ...snapshot,
+          previousVisibility: previous.visibility,
+          visibility: company.visibility,
+        },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, company: companyView(company) };
+    });
+  }
+
+  deleteCompany(input: {
+    actorId: string;
+    companyId: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ deletedId: string }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, 'company', input.companyId))) {
+        return NOT_FOUND;
+      }
+      const children = await tx
+        .select({ id: estates.id })
+        .from(estates)
+        .where(eq(estates.companyId, input.companyId))
+        .limit(1);
+      if (children.length > 0) return conflict('company still has estates');
+
+      // Snapshot and grants are read before the delete; target FKs cascade
+      // the grant rows, and each cascaded deletion is audited (§5.2).
+      const snapshot = await buildNodeSnapshot(tx, 'company', input.companyId);
+      const grants = await tx
+        .select()
+        .from(hierarchyGrants)
+        .where(eq(hierarchyGrants.companyId, input.companyId));
+
+      await tx.delete(companies).where(eq(companies.id, input.companyId));
+
+      const deleted = await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'delete',
+        targetKind: 'company',
+        targetId: input.companyId,
+        targetSnapshot: { ...snapshot },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      for (const grant of grants) {
+        await appendHierarchyEvent(tx, {
+          actorId: ctx.actorId,
+          verb: 'grant_revoke',
+          targetKind: 'grant',
+          targetId: grant.id,
+          targetSnapshot: grantSnapshot(grant),
+          correlationId: ctx.correlationId,
+          causationId: deleted.event.id,
+          idempotencyKey: `${ctx.idempotencyKey}:revoke:${grant.id}`,
+        });
+      }
+      return { ok: true, deletedId: input.companyId };
+    });
+  }
+
+  // ── estates ──────────────────────────────────────────────────────────────
+
+  /** Child creation requires owner on the parent and confers no grant (§4.3). */
+  createEstate(input: {
+    actorId: string;
+    companyId: string;
+    name: string;
+    slug: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ estate: NodeView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, 'company', input.companyId))) {
+        return NOT_FOUND;
+      }
+      const inserted = await tx
+        .insert(estates)
+        .values({ companyId: input.companyId, name: input.name, slug: input.slug })
+        .onConflictDoNothing()
+        .returning();
+      const estate = inserted[0];
+      if (!estate) return conflict('estate slug already exists in company');
+
+      const snapshot = await buildNodeSnapshot(tx, 'estate', estate.id);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'create',
+        targetKind: 'estate',
+        targetId: estate.id,
+        targetSnapshot: { ...snapshot },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, estate: { id: estate.id, name: estate.name, slug: estate.slug } };
+    });
+  }
+
+  renameEstate(input: {
+    actorId: string;
+    estateId: string;
+    name: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ estate: NodeView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, 'estate', input.estateId))) {
+        return NOT_FOUND;
+      }
+      const rows = await tx.select().from(estates).where(eq(estates.id, input.estateId)).limit(1);
+      const previous = rows[0];
+      if (!previous) return NOT_FOUND;
+
+      const updated = await tx
+        .update(estates)
+        .set({ name: input.name })
+        .where(eq(estates.id, input.estateId))
+        .returning();
+      const estate = updated[0] as typeof estates.$inferSelect;
+
+      const snapshot = await buildNodeSnapshot(tx, 'estate', estate.id);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'rename',
+        targetKind: 'estate',
+        targetId: estate.id,
+        targetSnapshot: { ...snapshot, previousName: previous.name },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, estate: { id: estate.id, name: estate.name, slug: estate.slug } };
+    });
+  }
+
+  /** Transfer requires effective owner on BOTH parents, evaluated in the transfer's own transaction (§5). */
+  transferEstate(input: {
+    actorId: string;
+    estateId: string;
+    destinationCompanyId: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ estate: NodeView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      const rows = await tx.select().from(estates).where(eq(estates.id, input.estateId)).limit(1);
+      const estate = rows[0];
+      if (!estate) return NOT_FOUND;
+      if (!(await this.requireOwner(tx, ctx.actorId, 'company', estate.companyId))) {
+        return NOT_FOUND;
+      }
+      if (!(await this.requireOwner(tx, ctx.actorId, 'company', input.destinationCompanyId))) {
+        return NOT_FOUND;
+      }
+      if (estate.companyId === input.destinationCompanyId) {
+        return conflict('estate already belongs to the destination company');
+      }
+      const collision = await tx
+        .select({ id: estates.id })
+        .from(estates)
+        .where(
+          and(eq(estates.companyId, input.destinationCompanyId), eq(estates.slug, estate.slug)),
+        )
+        .limit(1);
+      if (collision.length > 0) return conflict('destination company already has that estate slug');
+
+      const parents = await tx
+        .select({ id: companies.id, slug: companies.slug })
+        .from(companies)
+        .where(inArray(companies.id, [estate.companyId, input.destinationCompanyId]));
+      const source = parents.find((p) => p.id === estate.companyId);
+      const destination = parents.find((p) => p.id === input.destinationCompanyId);
+      if (!source || !destination) return NOT_FOUND;
+
+      await tx
+        .update(estates)
+        .set({ companyId: input.destinationCompanyId })
+        .where(eq(estates.id, input.estateId));
+
+      const snapshot = await buildNodeSnapshot(tx, 'estate', input.estateId);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'transfer',
+        targetKind: 'estate',
+        targetId: input.estateId,
+        targetSnapshot: { ...snapshot },
+        transferFrom: { kind: 'company', id: source.id, slug: source.slug },
+        transferTo: { kind: 'company', id: destination.id, slug: destination.slug },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, estate: { id: estate.id, name: estate.name, slug: estate.slug } };
+    });
+  }
+
+  deleteEstate(input: {
+    actorId: string;
+    estateId: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ deletedId: string }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, 'estate', input.estateId))) {
+        return NOT_FOUND;
+      }
+      const children = await tx
+        .select({ id: platformProjects.id })
+        .from(platformProjects)
+        .where(eq(platformProjects.estateId, input.estateId))
+        .limit(1);
+      if (children.length > 0) return conflict('estate still has platform projects');
+
+      const snapshot = await buildNodeSnapshot(tx, 'estate', input.estateId);
+      const grants = await tx
+        .select()
+        .from(hierarchyGrants)
+        .where(eq(hierarchyGrants.estateId, input.estateId));
+
+      await tx.delete(estates).where(eq(estates.id, input.estateId));
+
+      const deleted = await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'delete',
+        targetKind: 'estate',
+        targetId: input.estateId,
+        targetSnapshot: { ...snapshot },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      for (const grant of grants) {
+        await appendHierarchyEvent(tx, {
+          actorId: ctx.actorId,
+          verb: 'grant_revoke',
+          targetKind: 'grant',
+          targetId: grant.id,
+          targetSnapshot: grantSnapshot(grant),
+          correlationId: ctx.correlationId,
+          causationId: deleted.event.id,
+          idempotencyKey: `${ctx.idempotencyKey}:revoke:${grant.id}`,
+        });
+      }
+      return { ok: true, deletedId: input.estateId };
+    });
+  }
+
+  // ── platform projects ────────────────────────────────────────────────────
+
+  createPlatformProject(input: {
+    actorId: string;
+    estateId: string;
+    name: string;
+    slug: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ platformProject: NodeView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, 'estate', input.estateId))) {
+        return NOT_FOUND;
+      }
+      const inserted = await tx
+        .insert(platformProjects)
+        .values({ estateId: input.estateId, name: input.name, slug: input.slug })
+        .onConflictDoNothing()
+        .returning();
+      const project = inserted[0];
+      if (!project) return conflict('platform project slug already exists in estate');
+
+      const snapshot = await buildNodeSnapshot(tx, 'platform_project', project.id);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'create',
+        targetKind: 'platform_project',
+        targetId: project.id,
+        targetSnapshot: { ...snapshot },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return {
+        ok: true,
+        platformProject: { id: project.id, name: project.name, slug: project.slug },
+      };
+    });
+  }
+
+  renamePlatformProject(input: {
+    actorId: string;
+    platformProjectId: string;
+    name: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ platformProject: NodeView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (
+        !(await this.requireOwner(tx, ctx.actorId, 'platform_project', input.platformProjectId))
+      ) {
+        return NOT_FOUND;
+      }
+      const rows = await tx
+        .select()
+        .from(platformProjects)
+        .where(eq(platformProjects.id, input.platformProjectId))
+        .limit(1);
+      const previous = rows[0];
+      if (!previous) return NOT_FOUND;
+
+      const updated = await tx
+        .update(platformProjects)
+        .set({ name: input.name })
+        .where(eq(platformProjects.id, input.platformProjectId))
+        .returning();
+      const project = updated[0] as typeof platformProjects.$inferSelect;
+
+      const snapshot = await buildNodeSnapshot(tx, 'platform_project', project.id);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'rename',
+        targetKind: 'platform_project',
+        targetId: project.id,
+        targetSnapshot: { ...snapshot, previousName: previous.name },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return {
+        ok: true,
+        platformProject: { id: project.id, name: project.name, slug: project.slug },
+      };
+    });
+  }
+
+  transferPlatformProject(input: {
+    actorId: string;
+    platformProjectId: string;
+    destinationEstateId: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ platformProject: NodeView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      const rows = await tx
+        .select()
+        .from(platformProjects)
+        .where(eq(platformProjects.id, input.platformProjectId))
+        .limit(1);
+      const project = rows[0];
+      if (!project) return NOT_FOUND;
+      if (!(await this.requireOwner(tx, ctx.actorId, 'estate', project.estateId))) {
+        return NOT_FOUND;
+      }
+      if (!(await this.requireOwner(tx, ctx.actorId, 'estate', input.destinationEstateId))) {
+        return NOT_FOUND;
+      }
+      if (project.estateId === input.destinationEstateId) {
+        return conflict('platform project already belongs to the destination estate');
+      }
+      const collision = await tx
+        .select({ id: platformProjects.id })
+        .from(platformProjects)
+        .where(
+          and(
+            eq(platformProjects.estateId, input.destinationEstateId),
+            eq(platformProjects.slug, project.slug),
+          ),
+        )
+        .limit(1);
+      if (collision.length > 0) {
+        return conflict('destination estate already has that platform project slug');
+      }
+
+      const parents = await tx
+        .select({ id: estates.id, slug: estates.slug })
+        .from(estates)
+        .where(inArray(estates.id, [project.estateId, input.destinationEstateId]));
+      const source = parents.find((p) => p.id === project.estateId);
+      const destination = parents.find((p) => p.id === input.destinationEstateId);
+      if (!source || !destination) return NOT_FOUND;
+
+      await tx
+        .update(platformProjects)
+        .set({ estateId: input.destinationEstateId })
+        .where(eq(platformProjects.id, input.platformProjectId));
+
+      const snapshot = await buildNodeSnapshot(tx, 'platform_project', input.platformProjectId);
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'transfer',
+        targetKind: 'platform_project',
+        targetId: input.platformProjectId,
+        targetSnapshot: { ...snapshot },
+        transferFrom: { kind: 'estate', id: source.id, slug: source.slug },
+        transferTo: { kind: 'estate', id: destination.id, slug: destination.slug },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return {
+        ok: true,
+        platformProject: { id: project.id, name: project.name, slug: project.slug },
+      };
+    });
+  }
+
+  deletePlatformProject(input: {
+    actorId: string;
+    platformProjectId: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ deletedId: string }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (
+        !(await this.requireOwner(tx, ctx.actorId, 'platform_project', input.platformProjectId))
+      ) {
+        return NOT_FOUND;
+      }
+      const children = await tx
+        .select({ id: workspaces.id })
+        .from(workspaces)
+        .where(eq(workspaces.platformProjectId, input.platformProjectId))
+        .limit(1);
+      if (children.length > 0) return conflict('platform project still has workspaces');
+
+      const snapshot = await buildNodeSnapshot(tx, 'platform_project', input.platformProjectId);
+      const grants = await tx
+        .select()
+        .from(hierarchyGrants)
+        .where(eq(hierarchyGrants.platformProjectId, input.platformProjectId));
+
+      await tx.delete(platformProjects).where(eq(platformProjects.id, input.platformProjectId));
+
+      const deleted = await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'delete',
+        targetKind: 'platform_project',
+        targetId: input.platformProjectId,
+        targetSnapshot: { ...snapshot },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      for (const grant of grants) {
+        await appendHierarchyEvent(tx, {
+          actorId: ctx.actorId,
+          verb: 'grant_revoke',
+          targetKind: 'grant',
+          targetId: grant.id,
+          targetSnapshot: grantSnapshot(grant),
+          correlationId: ctx.correlationId,
+          causationId: deleted.event.id,
+          idempotencyKey: `${ctx.idempotencyKey}:revoke:${grant.id}`,
+        });
+      }
+      return { ok: true, deletedId: input.platformProjectId };
+    });
+  }
+
+  // ── grants ───────────────────────────────────────────────────────────────
+
+  /** Grant management requires effective owner on the target (§4.1). */
+  createGrant(input: {
+    actorId: string;
+    userId: string;
+    targetKind: GrantTargetKind;
+    targetId: string;
+    role: HierarchyGrantRole;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ grant: GrantView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      if (!(await this.requireOwner(tx, ctx.actorId, input.targetKind, input.targetId))) {
+        return NOT_FOUND;
+      }
+      const subject = await tx
+        .select({ id: users.id })
+        .from(users)
+        .where(eq(users.id, input.userId))
+        .limit(1);
+      if (subject.length === 0) return conflict('subject user does not exist');
+
+      const inserted = await tx
+        .insert(hierarchyGrants)
+        .values({
+          userId: input.userId,
+          companyId: input.targetKind === 'company' ? input.targetId : null,
+          estateId: input.targetKind === 'estate' ? input.targetId : null,
+          platformProjectId: input.targetKind === 'platform_project' ? input.targetId : null,
+          role: input.role,
+          grantedBy: ctx.actorId,
+        })
+        .onConflictDoNothing()
+        .returning();
+      const grant = inserted[0];
+      if (!grant) return conflict('grant already exists');
+
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'grant_create',
+        targetKind: 'grant',
+        targetId: grant.id,
+        targetSnapshot: grantSnapshot(grant),
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, grant: grantView(grant) };
+    });
+  }
+
+  changeGrant(input: {
+    actorId: string;
+    grantId: string;
+    role: HierarchyGrantRole;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ grant: GrantView }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      const rows = await tx
+        .select()
+        .from(hierarchyGrants)
+        .where(eq(hierarchyGrants.id, input.grantId))
+        .limit(1);
+      const existing = rows[0];
+      if (!existing) return NOT_FOUND;
+      const target = grantTarget(existing);
+      if (!(await this.requireOwner(tx, ctx.actorId, target.kind, target.id))) {
+        return NOT_FOUND;
+      }
+      // Team subjects are suspended (§1.4); the command surface never
+      // creates them, so this only fires on out-of-band rows.
+      if (!existing.userId) return conflict('team grant subjects are suspended');
+      if (existing.role === input.role) return conflict('grant already holds that role');
+
+      const duplicate = await tx
+        .select({ id: hierarchyGrants.id })
+        .from(hierarchyGrants)
+        .where(
+          and(
+            eq(hierarchyGrants.userId, existing.userId),
+            target.kind === 'company'
+              ? eq(hierarchyGrants.companyId, target.id)
+              : target.kind === 'estate'
+                ? eq(hierarchyGrants.estateId, target.id)
+                : eq(hierarchyGrants.platformProjectId, target.id),
+            eq(hierarchyGrants.role, input.role),
+          ),
+        )
+        .limit(1);
+      if (duplicate.length > 0) {
+        return conflict('subject already holds that role on the target');
+      }
+
+      const updated = await tx
+        .update(hierarchyGrants)
+        .set({ role: input.role })
+        .where(eq(hierarchyGrants.id, input.grantId))
+        .returning();
+      const grant = updated[0] as GrantRow;
+
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'grant_change',
+        targetKind: 'grant',
+        targetId: grant.id,
+        targetSnapshot: {
+          ...grantSnapshot(grant),
+          previousRole: namespacedHierarchyRole(existing.role as HierarchyGrantRole),
+        },
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, grant: grantView(grant) };
+    });
+  }
+
+  /** Revocation is row deletion (§6): the next evaluation denies, nothing lingers. */
+  revokeGrant(input: {
+    actorId: string;
+    grantId: string;
+    idempotencyKey?: string;
+  }): Promise<HierarchyResult<{ revokedId: string }>> {
+    return this.run(input.idempotencyKey, input.actorId, async (tx, ctx) => {
+      const rows = await tx
+        .select()
+        .from(hierarchyGrants)
+        .where(eq(hierarchyGrants.id, input.grantId))
+        .limit(1);
+      const existing = rows[0];
+      if (!existing) return NOT_FOUND;
+      const target = grantTarget(existing);
+      if (!(await this.requireOwner(tx, ctx.actorId, target.kind, target.id))) {
+        return NOT_FOUND;
+      }
+
+      await tx.delete(hierarchyGrants).where(eq(hierarchyGrants.id, input.grantId));
+
+      await appendHierarchyEvent(tx, {
+        actorId: ctx.actorId,
+        verb: 'grant_revoke',
+        targetKind: 'grant',
+        targetId: existing.id,
+        targetSnapshot: grantSnapshot(existing),
+        correlationId: ctx.correlationId,
+        idempotencyKey: ctx.idempotencyKey,
+      });
+      return { ok: true, revokedId: existing.id };
+    });
+  }
+
+  // ── reads ────────────────────────────────────────────────────────────────
+
+  /**
+   * The directory: every directory-class company, closed-field (§2.8). The
+   * sole ratified existence-disclosure carve-out (§6.7 / A2 §9.1.2).
+   */
+  async listDirectory(): Promise<DirectoryEntry[]> {
+    return this.db
+      .select({ id: companies.id, name: companies.name, slug: companies.slug })
+      .from(companies)
+      .where(eq(companies.visibility, 'directory'))
+      .orderBy(asc(companies.name));
+  }
+
+  /** Companies the user holds any grant on (company or descendant, §2.8). */
+  async listGrantedCompanies(userId: string): Promise<CompanyView[]> {
+    const ids = await grantedCompanyIds(this.db, userId);
+    if (ids.length === 0) return [];
+    const rows = await this.db
+      .select()
+      .from(companies)
+      .where(inArray(companies.id, ids))
+      .orderBy(asc(companies.name));
+    return rows.map(companyView);
+  }
+}

apps/gateway/src/hierarchy/hierarchy.service.ts

@@ -0,0 +1,31 @@
+import {
+  ConflictException,
+  ForbiddenException,
+  Injectable,
+  NotFoundException,
+} from '@nestjs/common';
+import type { HierarchyCommandFailure, HierarchyResult } from './hierarchy.repository.js';
+
+/**
+ * Maps repository result unions onto HTTP exceptions. `not_found` carries
+ * one fixed message for every cause — missing node and unauthorized caller
+ * are indistinguishable on the wire (contract 1 §6.7).
+ */
+@Injectable()
+export class HierarchyService {
+  unwrap<T>(result: HierarchyResult<T>): T {
+    if (result.ok) return result;
+    throw this.toException(result);
+  }
+
+  private toException(failure: HierarchyCommandFailure): Error {
+    switch (failure.error) {
+      case 'not_found':
+        return new NotFoundException('hierarchy node not found');
+      case 'forbidden':
+        return new ForbiddenException(failure.message);
+      case 'conflict':
+        return new ConflictException(failure.message);
+    }
+  }
+}

apps/gateway/src/mcp/mcp.service.spec.ts

@@ -176,7 +176,18 @@ describe('MCP actor identity and tool scope enforcement', () => {
     ).toBe(false);
     expect(
       deriveMcpToolScopesForUser({ role: 'platform-admin' }).has(MCP_TOOL_SCOPES.coord_list_tasks),
-    ).toBe(true);
+    ).toBe(false);
+  });
+
+  it('derives no scope elevation from any platform role (contract 2 §1.1 bypass retirement)', () => {
+    const memberScopes = deriveMcpToolScopesForUser({ role: 'member' });
+    for (const role of ['admin', 'platform-admin', 'super-admin', null, undefined]) {
+      const scopes = deriveMcpToolScopesForUser({ role });
+      expect([...scopes].sort()).toEqual([...memberScopes].sort());
+      expect(scopes.has(MCP_TOOL_SCOPES.brain_create_task)).toBe(false);
+      expect(scopes.has(MCP_TOOL_SCOPES.brain_update_task)).toBe(false);
+      expect(scopes.has(MCP_TOOL_SCOPES.coord_list_tasks)).toBe(false);
+    }
   });
 
   it('fails closed when scopes are not supplied by the authenticated context policy', () => {
@@ -311,14 +322,20 @@ describe('MCP actor identity and tool scope enforcement', () => {
     ]);
   });
 
-  it('enforces tenant boundaries for tenant-admin brain project, mission, and task reads', async () => {
-    const { service } = makeService({
+  it('gives admin-role and platform-admin-role actors only owned content on brain reads (§1.1 retirement)', async () => {
+    // Contract 2 §1.1: users.role confers no content visibility. An actor whose
+    // role is 'admin', 'platform-admin', or 'super-admin' but who holds no
+    // ownership sees exactly what an unprivileged member with the same
+    // ownership would see — here, only the one project they own, and nothing
+    // tenant-wide or platform-wide.
+    const fixtures = {
       projects: [
+        { id: 'project-owned', ownerId: 'role-bearing-user', teamId: 'tenant-a', name: 'owned' },
         {
           id: 'project-tenant-a',
           ownerId: 'other-user-a',
           teamId: 'tenant-a',
-          name: 'same tenant',
+          name: 'same tenant, unowned',
         },
         {
           id: 'project-tenant-b',
@@ -328,39 +345,50 @@ describe('MCP actor identity and tool scope enforcement', () => {
         },
       ],
       missions: [
+        { id: 'mission-owned', projectId: 'project-owned' },
         { id: 'mission-tenant-a', tenantId: 'tenant-a', projectId: 'project-tenant-a' },
         { id: 'mission-tenant-b', tenantId: 'tenant-b', projectId: 'project-tenant-b' },
       ],
       tasks: [
+        { id: 'task-owned', projectId: 'project-owned', status: 'not-started' },
         { id: 'task-tenant-a', projectId: 'project-tenant-a', status: 'not-started' },
         { id: 'task-tenant-b', projectId: 'project-tenant-b', status: 'not-started' },
       ],
-    });
-    const { server, tools } = makeCapturingServer();
-    const actor = makeAdminActor('tenant-admin-user', 'tenant-a');
+    };
 
-    service.registerTools(server, actor);
+    const actors = [
+      makeAdminActor('role-bearing-user', 'tenant-a'),
+      makePlatformAdminActor('role-bearing-user'),
+    ];
 
-    const projects = JSON.parse(
-      (await getTool(tools, 'brain_list_projects').handler({})).content[0]!.text,
-    );
-    expect(projects.map((project: { id: string }) => project.id)).toEqual(['project-tenant-a']);
+    for (const actor of actors) {
+      const { service } = makeService(fixtures);
+      const { server, tools } = makeCapturingServer();
+      service.registerTools(server, actor);
 
-    const missions = JSON.parse(
-      (await getTool(tools, 'brain_list_missions').handler({})).content[0]!.text,
-    );
-    expect(missions.map((mission: { id: string }) => mission.id)).toEqual(['mission-tenant-a']);
+      const projects = JSON.parse(
+        (await getTool(tools, 'brain_list_projects').handler({})).content[0]!.text,
+      );
+      expect(projects.map((project: { id: string }) => project.id)).toEqual(['project-owned']);
 
-    const tasks = JSON.parse(
-      (await getTool(tools, 'brain_list_tasks').handler({})).content[0]!.text,
-    );
-    expect(tasks.map((task: { id: string }) => task.id)).toEqual(['task-tenant-a']);
+      const missions = JSON.parse(
+        (await getTool(tools, 'brain_list_missions').handler({})).content[0]!.text,
+      );
+      expect(missions.map((mission: { id: string }) => mission.id)).toEqual(['mission-owned']);
+
+      const tasks = JSON.parse(
+        (await getTool(tools, 'brain_list_tasks').handler({})).content[0]!.text,
+      );
+      expect(tasks.map((task: { id: string }) => task.id)).toEqual(['task-owned']);
+    }
   });
 
   it('denies tenant-admin task writes outside the authenticated tenant', async () => {
     const { service, brain } = makeService({
       projects: [
-        { id: 'project-tenant-a', ownerId: 'other-user-a', teamId: 'tenant-a' },
+        // §1.1 retirement: content visibility comes from ownership, not the
+        // tenant-admin role — the acting user owns the tenant-a project.
+        { id: 'project-tenant-a', ownerId: 'tenant-admin-user', teamId: 'tenant-a' },
         { id: 'project-tenant-b', ownerId: 'other-user-b', teamId: 'tenant-b' },
       ],
       missions: [
@@ -373,7 +401,29 @@ describe('MCP actor identity and tool scope enforcement', () => {
       ],
     });
     const { server, tools } = makeCapturingServer();
-    const actor = makeAdminActor('tenant-admin-user', 'tenant-a');
+    // Platform role no longer derives task-write scopes (§1.1 retirement):
+    // a role-derived admin actor is scope-denied before any tenant logic.
+    const roleDerivedAdmin = makeAdminActor('tenant-admin-user', 'tenant-a');
+    service.registerTools(server, roleDerivedAdmin);
+    await expect(
+      getTool(tools, 'brain_create_task').handler({ title: 'role-derived write' }),
+    ).rejects.toThrow('MCP tool scope denied');
+    expect(brain.tasks.create).not.toHaveBeenCalled();
+
+    // The tenant-scoping checks below sit behind the scope gate; exercise
+    // them with explicitly granted task-write scopes (how grant-mapped
+    // scopes will arrive), not with a platform role.
+    tools.clear();
+    const actor = createMcpActorContext({
+      userId: 'tenant-admin-user',
+      tenantId: 'tenant-a',
+      role: 'member',
+      scopes: [
+        ...deriveMcpToolScopesForUser({ role: 'member' }),
+        MCP_TOOL_SCOPES.brain_create_task,
+        MCP_TOOL_SCOPES.brain_update_task,
+      ],
+    });
 
     service.registerTools(server, actor);
 
@@ -416,7 +466,7 @@ describe('MCP actor identity and tool scope enforcement', () => {
     );
   });
 
-  it('keeps admin-only coordination tools on server-derived paths', async () => {
+  it('denies coordination tools to every role-derived actor and keeps the granted path server-derived', async () => {
     const { service, coord } = makeService();
     const { server, tools } = makeCapturingServer();
     const member = makeMemberActor('authenticated-user');
@@ -433,10 +483,25 @@ describe('MCP actor identity and tool scope enforcement', () => {
     const tenantAdminTool = getTool(tools, 'coord_list_tasks');
     await expect(tenantAdminTool.handler({})).rejects.toThrow('MCP tool scope denied: coord:read');
 
+    // §1.1 retirement: platform-admin no longer derives coord scopes either.
     tools.clear();
     service.registerTools(server, platformAdmin);
     const platformAdminTool = getTool(tools, 'coord_list_tasks');
-    await platformAdminTool.handler({ projectPath: '/tmp/victim' });
+    await expect(platformAdminTool.handler({})).rejects.toThrow(
+      'MCP tool scope denied: coord:read',
+    );
+
+    // An explicitly granted coord:read scope reaches the server-derived
+    // path (caller-supplied projectPath is stripped by the schema).
+    tools.clear();
+    const grantedActor = createMcpActorContext({
+      userId: 'granted-user',
+      role: 'member',
+      scopes: [MCP_TOOL_SCOPES.coord_list_tasks],
+    });
+    service.registerTools(server, grantedActor);
+    const grantedTool = getTool(tools, 'coord_list_tasks');
+    await grantedTool.handler({ projectPath: '/tmp/victim' });
     expect(coord.listTasks).toHaveBeenCalledWith(process.cwd());
   });
 

apps/gateway/src/mcp/mcp.service.ts

@@ -63,20 +63,6 @@ interface SessionEntry {
   actor: McpActorContext;
 }
 
-const GLOBAL_ADMIN_MCP_SCOPES = new Set<McpToolScope>(Object.values(MCP_TOOL_SCOPES));
-const TENANT_ADMIN_MCP_SCOPES = new Set<McpToolScope>([
-  MCP_TOOL_SCOPES.brain_list_projects,
-  MCP_TOOL_SCOPES.brain_get_project,
-  MCP_TOOL_SCOPES.brain_list_tasks,
-  MCP_TOOL_SCOPES.brain_create_task,
-  MCP_TOOL_SCOPES.brain_update_task,
-  MCP_TOOL_SCOPES.brain_list_missions,
-  MCP_TOOL_SCOPES.brain_list_conversations,
-  MCP_TOOL_SCOPES.memory_search,
-  MCP_TOOL_SCOPES.memory_get_preferences,
-  MCP_TOOL_SCOPES.memory_save_preference,
-  MCP_TOOL_SCOPES.memory_save_insight,
-]);
 const MEMBER_MCP_SCOPES = new Set<McpToolScope>([
   MCP_TOOL_SCOPES.brain_list_projects,
   MCP_TOOL_SCOPES.brain_get_project,
@@ -89,15 +75,17 @@ const MEMBER_MCP_SCOPES = new Set<McpToolScope>([
   MCP_TOOL_SCOPES.memory_save_insight,
 ]);
 
-export function deriveMcpToolScopesForUser(input: {
+/**
+ * Contract 2 §1.1: platform role confers NO MCP scope elevation — the
+ * former tenant-admin/global-admin scope sets keyed on users.role are
+ * retired. Every authenticated user receives the base member set; task
+ * writes and coordination scopes attach to explicit hierarchy grants when
+ * the MCP grant mapping lands, never to a platform role. The role
+ * parameter is kept for caller compatibility and deliberately ignored.
+ */
+export function deriveMcpToolScopesForUser(_input: {
   role?: string | null;
 }): ReadonlySet<McpToolScope> {
-  if (input.role === 'platform-admin' || input.role === 'super-admin') {
-    return new Set(GLOBAL_ADMIN_MCP_SCOPES);
-  }
-  if (input.role === 'admin') {
-    return new Set(TENANT_ADMIN_MCP_SCOPES);
-  }
   return new Set(MEMBER_MCP_SCOPES);
 }
 
@@ -168,41 +156,22 @@ type TaskLike = TenantScopedLike & {
   userId?: string | null;
 };
 
-function isGlobalAdminActor(actor: McpActorContext): boolean {
-  return actor.role === 'platform-admin' || actor.role === 'super-admin';
-}
-
-function isTenantAdminActor(actor: McpActorContext): boolean {
-  return actor.role === 'admin';
-}
-
-function matchesTenant(actor: McpActorContext, record: TenantScopedLike): boolean {
-  return (
-    record.tenantId === actor.tenantId ||
-    record.organizationId === actor.tenantId ||
-    record.teamId === actor.tenantId
-  );
-}
-
+/**
+ * Contract 2 §1.1: `users.role` confers NO content visibility — the former
+ * global-admin/tenant-admin filter short-circuits keyed on the platform role
+ * are retired along with the role-derived scope sets. Content reaches an MCP
+ * actor through ownership only; widened access arrives as explicit hierarchy
+ * grants when the MCP grant mapping lands.
+ */
 function filterProjectsForActor<T extends ProjectLike>(actor: McpActorContext, projects: T[]): T[] {
-  if (isGlobalAdminActor(actor)) return projects;
-  return projects.filter(
-    (project) =>
-      project.ownerId === actor.userId ||
-      (isTenantAdminActor(actor) && matchesTenant(actor, project)),
-  );
+  return projects.filter((project) => project.ownerId === actor.userId);
 }
 
 function filterMissionsByDirectActorScope<T extends MissionLike>(
   actor: McpActorContext,
   missions: T[],
 ): T[] {
-  if (isGlobalAdminActor(actor)) return missions;
-  return missions.filter(
-    (mission) =>
-      mission.userId === actor.userId ||
-      (isTenantAdminActor(actor) && matchesTenant(actor, mission)),
-  );
+  return missions.filter((mission) => mission.userId === actor.userId);
 }
 
 function scopesEqual(left: ReadonlySet<McpToolScope>, right: ReadonlySet<McpToolScope>): boolean {
@@ -293,7 +262,6 @@ export class McpService implements OnModuleDestroy {
   }
 
   private async isProjectAuthorized(actor: McpActorContext, projectId: string): Promise<boolean> {
-    if (isGlobalAdminActor(actor)) return true;
     const project = (await this.brain.projects.findById(projectId)) as ProjectLike | undefined;
     return project ? filterProjectsForActor(actor, [project]).length === 1 : false;
   }
@@ -302,8 +270,6 @@ export class McpService implements OnModuleDestroy {
     actor: McpActorContext,
     missions: T[],
   ): Promise<T[]> {
-    if (isGlobalAdminActor(actor)) return missions;
-
     const projects = (await this.brain.projects.findAll()) as ProjectLike[];
     const projectIds = new Set(
       filterProjectsForActor(actor, projects).map((project) => project.id),
@@ -317,7 +283,6 @@ export class McpService implements OnModuleDestroy {
   }
 
   private async isMissionAuthorized(actor: McpActorContext, missionId: string): Promise<boolean> {
-    if (isGlobalAdminActor(actor)) return true;
     const mission = (await this.brain.missions.findById(missionId)) as MissionLike | undefined;
     if (!mission) return false;
     return (await this.filterMissionsForActor(actor, [mission])).length === 1;
@@ -339,7 +304,7 @@ export class McpService implements OnModuleDestroy {
     actor: McpActorContext,
     refs: { projectId?: string | null; missionId?: string | null },
   ): Promise<void> {
-    if (!isGlobalAdminActor(actor) && !refs.projectId && !refs.missionId) {
+    if (!refs.projectId && !refs.missionId) {
       throw new Error('MCP task scope denied');
     }
     await this.assertTaskReferencesAuthorized(actor, refs);
@@ -349,8 +314,6 @@ export class McpService implements OnModuleDestroy {
     actor: McpActorContext,
     tasks: T[],
   ): Promise<T[]> {
-    if (isGlobalAdminActor(actor)) return tasks;
-
     const [projects, missions] = await Promise.all([
       this.brain.projects.findAll(),
       this.brain.missions.findAll(),
@@ -367,7 +330,6 @@ export class McpService implements OnModuleDestroy {
     return tasks.filter(
       (task) =>
         task.userId === actor.userId ||
-        (isTenantAdminActor(actor) && matchesTenant(actor, task)) ||
         (typeof task.projectId === 'string' && projectIds.has(task.projectId)) ||
         (typeof task.missionId === 'string' && missionIds.has(task.missionId)),
     );

apps/gateway/src/validation-pipe-check.ts

@@ -1,6 +1,18 @@
 import 'reflect-metadata';
 import { getMetadataStorage } from 'class-validator';
 import { BootstrapSetupDto } from './admin/bootstrap.dto.js';
+import {
+  ChangeCompanyVisibilityDto,
+  ChangeGrantDto,
+  CreateCompanyDto,
+  CreateEstateDto,
+  CreateGrantDto,
+  CreatePlatformProjectDto,
+  DeleteNodeDto,
+  RenameNodeDto,
+  TransferEstateDto,
+  TransferPlatformProjectDto,
+} from './hierarchy/hierarchy.dto.js';
 
 /**
  * Boot-time self-check: the global ValidationPipe must be able to SEE the
@@ -43,6 +55,56 @@ export const PIPE_GUARDED_DTOS: Array<{
     target: BootstrapSetupDto,
     properties: ['name', 'email', 'password'],
   },
+  {
+    name: 'CreateCompanyDto',
+    target: CreateCompanyDto,
+    properties: ['name', 'slug', 'idempotencyKey'],
+  },
+  {
+    name: 'RenameNodeDto',
+    target: RenameNodeDto,
+    properties: ['name', 'idempotencyKey'],
+  },
+  {
+    name: 'ChangeCompanyVisibilityDto',
+    target: ChangeCompanyVisibilityDto,
+    properties: ['visibility', 'idempotencyKey'],
+  },
+  {
+    name: 'DeleteNodeDto',
+    target: DeleteNodeDto,
+    properties: ['idempotencyKey'],
+  },
+  {
+    name: 'CreateEstateDto',
+    target: CreateEstateDto,
+    properties: ['companyId', 'name', 'slug', 'idempotencyKey'],
+  },
+  {
+    name: 'CreatePlatformProjectDto',
+    target: CreatePlatformProjectDto,
+    properties: ['estateId', 'name', 'slug', 'idempotencyKey'],
+  },
+  {
+    name: 'TransferEstateDto',
+    target: TransferEstateDto,
+    properties: ['destinationCompanyId', 'idempotencyKey'],
+  },
+  {
+    name: 'TransferPlatformProjectDto',
+    target: TransferPlatformProjectDto,
+    properties: ['destinationEstateId', 'idempotencyKey'],
+  },
+  {
+    name: 'CreateGrantDto',
+    target: CreateGrantDto,
+    properties: ['userId', 'targetKind', 'targetId', 'role', 'idempotencyKey'],
+  },
+  {
+    name: 'ChangeGrantDto',
+    target: ChangeGrantDto,
+    properties: ['role', 'idempotencyKey'],
+  },
 ];
 
 export class PipeMetatypeCheckError extends Error {

docs/requirements/hierarchy-schema.md

@@ -72,6 +72,25 @@ example now lists the complete measured set, and the import analysis
 is extended to resolve literal dynamic `import()` routes, which two of
 the four members use.
 
+Amendment 1 (Ruling 4b, 2026-08-28): company visibility classes. The
+directory exists so one shared company can serve many users instead of
+each user creating a duplicate private company (Ruling 4b, webui-audit
+lane, ruled 2026-08-27). §2.1 gains a `visibility` column; §2.8 defines
+the two classes (`private`/`directory`), the directory's existence-only
+disclosure, and the pre-binding invariants for the deferred
+see-and-ask-to-join flow (no join-request surface is authorized here —
+its flow is a follow-up contract); §5.2's mutation
+enumeration gains the visibility change; §5.5 defines who may change
+visibility (platform admins, plus a company-CRUD capability whose
+definition is a follow-up amendment to contract 2 — until it ratifies,
+admin-only); §6.1 and §6.9 add the witnesses; §6.7's existence-oracle
+rule is scoped around the ratified directory carve-out. Top-level
+creation (contract 3 §5.2) is unchanged and always yields a private
+company. Upstream, SOT Amendment A2 (native-kanban-sot.md §9, this PR)
+expressly extends A1 §8.1.2 to admit the visibility column and A1
+§8.1.3 to admit the directory function — this contract relies on that
+amendment, not on a reinterpretation of A1.
+
 Scope: the tenancy/authorization structure record class — companies,
 estates, platform-projects, workspaces, hierarchy grants, their parentage,
 and constraints. Out of scope: the RBAC grant vocabulary and evaluation
@@ -86,8 +105,13 @@ legacy flat data (future work; see §1.3).
    AND `hierarchy_grants` (§3) — A1 includes hierarchy-level access grants
    in the class. Every rule addressed to "the class" in this contract
    (payload prohibition, mutation path, audit) binds all five tables. Class
-   rows carry parentage, naming, grant, and audit-linkage data only — never
-   task, plan, or any business/orchestration payload.
+   rows carry parentage, naming, grant, audit-linkage, and visibility-class
+   data only — never task, plan, or any business/orchestration payload.
+   Visibility (`companies.visibility`, §2.8) is admitted into that
+   enumeration by SOT Amendment A2 §9.1.1, which expressly extends A1
+   §8.1.2 for exactly this one column: it is disclosure data about the
+   class's own nodes — not a payload field, carries no business content,
+   and widens the payload prohibition for nothing else.
    References from business/orchestration rows into the class are limited
    to exactly one form: the canonical `workspace_id` tenancy column that
    REQ-TEN-001 requires on every canonical row, referencing
@@ -116,7 +140,9 @@ MUST NOT merge the two. (A rename of either remains an implementation-PR
 decision under A1; this contract pins only that they stay distinct tables.)
 
 1. `companies` — id (uuid pk), name, slug (unique per deployment),
-   created_at, updated_at. N per deployment (D2).
+   `visibility` (text NOT NULL, DEFAULT `private`, CHECK constrained to
+   exactly `private` | `directory`; semantics §2.8), created_at,
+   updated_at. N per deployment (D2).
 2. `estates` — id, name, slug, `company_id` NOT NULL →
    `companies.id` ON DELETE RESTRICT. Exactly one company per estate; a
    company holds any number of estates.
@@ -142,6 +168,31 @@ decision under A1; this contract pins only that they stay distinct tables.)
    free-form payload field. The columns declared in this section and §3
    are exhaustive: a class table's column set is exactly its declared set
    (verified per §6.2) — nothing else (A1 §8.1.2).
+8. **Company visibility classes (Ruling 4b).** Every company is exactly
+   one of two classes, carried by `visibility`:
+   - `private` (the default): the company is disclosed only to subjects
+     holding a grant on it or on a descendant — the resting state every
+     company is created in. Open creation under contract 3 §5.2
+     (Ruling 4) survives unchanged: it creates private companies.
+   - `directory`: the company is listed in the deployment-wide company
+     directory. Directory listing discloses **existence, name, and slug
+     to every authenticated user — nothing else**: no subtree structure,
+     no roll-up aggregates, no workspace content, no grant or membership
+     information.
+     Visibility is disclosure, not authority. Content and structure access
+     to a directory-listed company still require explicit grants —
+     contract 2 §3.1 deny-by-default is unchanged, and the ownership model
+     (§4.4, contract 2 §4.3) is unchanged. Ruling 4b decision 5 wants a
+     see-and-ask-to-join flow for directory-listed companies. **This
+     contract authorizes no join-request runtime surface**: the flow in
+     its entirety — the ability to submit a request, its transport,
+     storage, and request lifecycle — is a follow-up contract, and until
+     that contract ratifies, the directory's only function is the
+     read-only listing above (A2 §9.1.2 admits nothing more). Two
+     invariants pre-bind that future contract now:
+     a join request confers no authority of any kind, and approval is
+     ordinary grant creation by an effective `owner` under contract 2 §4.1
+     — there is no other acceptance path.
 
 ## 3. Grant attachment points
 
@@ -223,7 +274,8 @@ shape contract 2 attaches to:
 2. **Audit parity.** A1 §8.2 leaves every pre-existing REQ binding, so
    hierarchy mutations get REQ-AUD-001's guarantees, not a weakened
    substitute. Concretely:
-   - Every create, rename, transfer, grant create/change/revoke, and
+   - Every create, rename, transfer, visibility change (§5.5), grant
+     create/change/revoke, and
      delete — including every grant deletion cascaded by a node delete —
      emits a semantic audit event carrying actor, verb, target, and (for
      transfers) source and destination parents, with the correlation,
@@ -248,6 +300,25 @@ shape contract 2 attaches to:
    workspace work. Contract 8 owns projection details but cannot narrow
    this rule. This contract additionally guarantees the chain roll-ups
    aggregate over is unique and non-null (§2.5).
+5. **Visibility administration (Ruling 4b decisions 2–3).** Changing
+   `companies.visibility` is a hierarchy mutation through the §5.1
+   command path, audited per §5.2 (the event carries the old and new
+   visibility values as its semantic content). It is authorized for
+   exactly two actor classes: platform admins (`users.role = 'admin'`)
+   and subjects holding the company-CRUD capability that a follow-up
+   amendment to contract 2 will define — until that amendment ratifies,
+   the capability class is empty and the command is admin-only.
+   A company `owner` as such may NOT change visibility: standard users
+   cannot publish a company into the directory. This is the one
+   hierarchy mutation a platform admin performs without holding a
+   hierarchy grant, and it is ratified here as instance administration
+   (directory curation) in contract 2 §1.1's sense, not tenant access:
+   the command mutates the single `visibility` column, reads no tenant
+   content, and confers no grant — contract 2 §1.1's
+   no-implicit-tenant-access rule is otherwise untouched. Top-level
+   company creation (contract 3 §5.2) always creates
+   `visibility = 'private'`; the creation command cannot set or change
+   visibility.
 
 ## 6. Verification requirements
 
@@ -264,7 +335,10 @@ Binding on the implementing PRs (extends A1 §8.3):
    witnessed (zero and two set → refused). Grant uniqueness: a duplicate
    (subject, target, role) row refused for each of the six subject×target
    forms, proving NULLS-NOT-DISTINCT semantics; NOT NULL on `role`,
-   `granted_by`, and all `name`/`slug` columns witnessed.
+   `granted_by`, and all `name`/`slug` columns witnessed. Company
+   visibility (§2.8): a value outside `private`/`directory` refused with
+   both valid values accepted as the control; an insert omitting the
+   column defaults to `private`.
 2. Column allowlist: an information_schema assertion that each class
    table's column set is exactly the set declared in §2/§3 — the bounded
    observable for no-payload (§2.7) and no-`owner_id` (§4.4).
@@ -346,9 +420,19 @@ Binding on the implementing PRs (extends A1 §8.3):
    static analysis cannot see, and any such evasion found later is
    corrected as a conformance defect, not grandfathered.
 4. Audit witnesses: for each mutation class (create, rename, transfer,
-   grant create/change/revoke, delete) — the event exists after commit
-   with actor/verb/target and same-transaction atomicity; a rolled-back
-   mutation leaves no event (rollback witness); a node delete's cascaded
+   visibility change, grant create/change/revoke, delete) — the event
+   exists after commit
+   with actor/verb/target and same-transaction atomicity, and the
+   event's outbox record exists after the same commit — state row,
+   audit event, and outbox record are witnessed as one transaction
+   (REQ-AUD-001); a rolled-back
+   mutation leaves no event, no outbox record, AND no state effect —
+   a rolled-back create leaves no row, a rolled-back rename, transfer,
+   or visibility change leaves the prior values in place, and a
+   rolled-back delete or grant revoke leaves the row present
+   (rollback witness on all three legs, per REQ-AUD-001's
+   commit-or-roll-back-together acceptance); a
+   node delete's cascaded
    grant deletions are each covered by events; events survive deletion of
    their target (query the events of a deleted node).
 5. Transfer tests: parent-FK update moves the subtree resolution and
@@ -368,10 +452,30 @@ Binding on the implementing PRs (extends A1 §8.3):
    endpoints mutate no canonical state anywhere (assert zero writes across
    hierarchy AND workspace tables, not hierarchy only); readers see
    aggregates only over workspaces they are authorized on, with no
-   cross-tenant existence oracles (A1 §8.3 acceptance 3).
+   cross-tenant existence oracles (A1 §8.3 acceptance 3, as narrowed by
+   A2 §9.1.2) beyond the one
+   ratified carve-out — the §2.8 company directory, witnessed in §6.9.
 8. Real-PostgreSQL coverage for every constraint witness (unique/CHECK/
    RESTRICT/NULLS NOT DISTINCT behavior), using the `ci-postgres` service
    in the `test` CI step; mocked specs cannot witness database constraints.
+9. Visibility witnesses (§2.8, §5.5): the directory read returns exactly
+   the `visibility = 'directory'` companies to any authenticated user,
+   disclosing existence, name, and slug only (closed-field assertion on
+   the response shape); a private company never appears in the directory
+   for a reader without a grant on it (with the control: it appears in
+   that reader's granted-structure reads); a directory-listed company's
+   subtree, aggregates, and content remain refused for a non-granted
+   reader (disclosure ≠ authority); the visibility command is refused
+   for a non-admin actor — including an effective `owner` of the target
+   company — with the platform-admin accept control; top-level creation
+   yields `visibility = 'private'` and accepts no visibility argument;
+   each visibility change emits its §5.2 audit event carrying old and
+   new values — the full audit pattern for the mutation class
+   (same-transaction atomicity of state row, audit event, and outbox
+   record; rollback leaving no state effect, no event, and no outbox
+   record; actor/verb/target) is §6.4's, which enumerates
+   visibility change; this item adds only the old/new-value payload
+   assertion.
 
 ## Ruling request
 

docs/requirements/mode-conversion.md

@@ -0,0 +1,279 @@
+# Deployment Mode and Conversion Contract (D3)
+
+Status: DRAFT — awaiting ratification (webui-audit S2, contract 6 of 9).
+Authority: PRD D3 (Part I §3) — two modes chosen at install time,
+Standalone and Enterprise, with the mode table (brains, user-data
+isolation, secrets, conversion); Standalone → Enterprise conversion is
+**one-way** and Enterprise is a **terminal state**. PRD D14 (Part I §7)
+— the per-user brain split is optional in Standalone and keeping it is
+the recommended default because it preserves forward-compatibility with
+the one-way conversion. PRD D11 (Part I §9) — v1 ships the Standalone
+flow only; Enterprise conversion is explicitly deferred. PRD D3
+federation clause — federation is intentionally not fully designed,
+deferred, and nothing in v1 may foreclose it.
+
+Revision 2 (luna review F1–F7): the identity precondition restated in
+identity-contract terms with a conversion-local acknowledgment record
+this contract owns (F1); a durable, keyed preparation state with a
+Standalone-safe representation rule, an in-transaction re-check fence,
+and an exact flip boundary (F2); the §5.4 unknown-value rule stated
+directly without the contradictory non-exhaustiveness clause (F3); the
+D14 boundary bound here with a stable column-allowlist witness instead
+of delegated to an unratified layout (F4); the conversion witness
+matrix extended to every §4.2/§4.4 condition (F5); the mode-record
+writer coverage imported concretely from contract 1 §6.3 with a named
+schema, closed writer set, crafted-write probe, and mode-resolution
+assertion (F6); the mode read command flagged as a §12.1 drafting
+addition rather than a D8 mandate (F7). Ownership language aligned
+with contract 3 revision 2: mode is recorded at bootstrap and read by
+the wizard as input.
+
+This contract binds the mode as a canonical platform property (§2), the
+per-mode obligations and which contract owns each (§3), the conversion
+transition (§4), the v1 non-foreclosure obligations (§5), and their
+witnesses (§6). Domain semantics stay with their owning contracts:
+wizard branching (contract 3 §2), identity/SSO
+(`identity-lifecycle.md`), custody and per-user brain mechanics
+(contract 7, `custody-schema.md`), tool mapping
+(`tool-gateway-mapping.md`).
+
+## 1. Definitions
+
+1. **Mode**: the platform-wide deployment mode, exactly one of
+   `standalone` or `enterprise`. The vocabulary is closed in v1;
+   extension (e.g. a federation mode) is by amendment to this contract,
+   never ad hoc.
+2. **Conversion**: the one-way transition `standalone → enterprise`.
+   No other mode transition exists.
+3. **Conversion preconditions**: the verifiable conditions of §4.2 that
+   must all hold before the mode record may change.
+4. **Preparation unit**: one re-runnable piece of pre-conversion work —
+   the migration of one secret to the Vault backend, or the partition
+   of one user's brain content (§4.3).
+
+## 2. Mode is a canonical recorded property
+
+1. Mode is recorded canonically in the platform database at bootstrap
+   as the operator's install-time choice (D3: modes are "chosen at
+   install time"). The record is a single-row keyed record
+   (`platform_mode`: mode value, recorded-at timestamp, bootstrap epoch
+   reference); this contract owns it, the bootstrap writer performs the
+   one v1 write (§6.2), and the wizard reads it as input (contract 3
+   §2.3). Mode is never derived from feature state (presence of Vault,
+   count of brains, count of users), and no component may infer a
+   different mode than the record states.
+2. The record is readable by any authenticated user through a Gateway
+   command with CLI exposure. This read command is a **drafting
+   addition** ratified with this contract (PRD §12.1), not a D8
+   mandate: D8 binds only that any surface exposing the value goes
+   through official tooling. When a webUI surface consumes the read, a
+   mapping row is added to `tool-gateway-mapping.md` by amendment —
+   the same route §4.4 already binds for the conversion command.
+   Components branch on the read value only.
+3. The record is immutable except by the §4 conversion transition.
+   Editing it by direct database access, config file, environment
+   variable, or wizard re-run is non-conformant (contract 3 §2.3:
+   changing mode later is conversion, not a wizard re-run).
+
+## 3. Per-mode obligations (owner map)
+
+The PRD mode table binds four rows; this contract assigns each an
+owning contract so no obligation is unowned and none is bound twice:
+
+| Obligation          | Standalone                             | Enterprise                                         | Owner                                         |
+| ------------------- | -------------------------------------- | -------------------------------------------------- | --------------------------------------------- |
+| Brains              | one mosaic-brain (system + user files) | system brain for config + one brain per user       | contract 7 (custody/brain mechanics)          |
+| User-data isolation | single user                            | no user-data leakage between users; sharing opt-in | contract 7 (enforced by architecture, D14)    |
+| Secrets             | OpenBao/Vault or flat files            | OpenBao/Vault REQUIRED                             | this contract (§4.2 gate; steady-state check) |
+| Conversion          | may convert to Enterprise, one-way     | terminal state                                     | this contract (§4)                            |
+
+The Standalone brains row states the default layout, not the only
+valid one: the D14 per-user split is a MAY in Standalone with keeping
+it the recommended default (PRD §7, contract 7 §6), and Vault-backed
+secrets are equally valid Standalone configuration. Both prepared
+states are therefore themselves valid Standalone states — the fact
+§4.3 relies on.
+
+In Enterprise steady state, a flat-file secrets backend is
+non-conformant; the platform refuses to start Enterprise-mode
+components against a flat-file secrets configuration (fail-closed, not
+warn-and-run).
+
+## 4. Conversion transition
+
+1. **Direction and terminality.** The only transition is
+   `standalone → enterprise`. `enterprise → standalone` does not exist:
+   there is no command, no admin override, and no support path. An
+   attempt is refused with the precondition/state error class of the
+   command envelope (`tool-gateway-mapping.md` §4.2).
+2. **Preconditions (all verified before the record changes):**
+   - Secrets: OpenBao/Vault is configured and reachable, and every
+     required secret is served from the Vault backend — none from a
+     flat-file backend. Secret migration completes before conversion;
+     this contract does not define the migration tooling, only the
+     gate.
+   - Brains: the per-user brain split required by the Enterprise row of
+     §3 is established for **every** existing user (or the deployment
+     already kept the split, the D14 recommended default). Brain
+     partitioning mechanics are contract 7; this contract binds only
+     that the split is complete before the mode flips.
+   - Identity: at least one platform administrator account exists that
+     is active in identity-contract terms — authenticated capability,
+     not banned, not deactivated (identity §2, §5). And the conversion
+     request carries a **configuration acknowledgment**: the current
+     canonical values of registration mode and per-provider JIT
+     enablement (identity §2.2, §4.1), echoed back in the request. A
+     mismatch between the echoed values and the canonical values at
+     verification refuses the conversion. This acknowledgment record
+     is conversion-local, owned by this contract, and stored with the
+     §4.4 audit event as the precondition evidence; it adds no
+     identity-contract obligation and no mode-specific identity
+     default — identity's own defaults remain valid states.
+3. **Preparation state and the flip boundary.** Preparatory work is
+   tracked durably: each preparation unit (§1.4) records its
+   completion in a preparation table keyed by (bootstrap epoch, unit
+   identity — the secret's path, the user's id), written in the same
+   transaction as the unit's own effect where the unit's backend
+   allows it, and reconciled from the backend's actual state where it
+   does not (a secret already served by Vault, a brain already split,
+   is complete regardless of the table). Units are at-most-once per
+   key and re-runnable across attempts. **Standalone-safe
+   representation:** every preparation unit moves the deployment into
+   a state that is itself valid Standalone configuration (§3 note), so
+   an interrupted preparation leaves a fully operational Standalone
+   deployment reading its state through the ordinary contracts — no
+   rollback, fencing, or special Standalone read path is needed, and
+   no component behavior may key on "preparation in progress".
+   **The flip:** one transaction that (a) locks the mode record, (b)
+   re-verifies every §4.2 precondition after acquiring the lock, and
+   (c) writes the mode record and the §4.4 audit event. Any re-check
+   failure aborts with no write. External state that changes after the
+   re-check but before commit is bounded by the transaction window;
+   an external backend (Vault) failing after conversion is an
+   Enterprise runtime fault handled by §3's fail-closed steady-state
+   rule, not a conversion defect. An interrupted or failed conversion
+   leaves the record `standalone` and the platform fully operational;
+   there is no intermediate mode and no half-converted state
+   observable through the record.
+4. **Authority and audit.** Conversion is a platform-administrator
+   command carrying an explicit irreversibility acknowledgment in its
+   request (distinct from the §4.2 configuration acknowledgment). It
+   is an official Gateway/CLI command (D8): when built, it is added to
+   the tool↔Gateway mapping by amendment (`tool-gateway-mapping.md`
+   §3.3). The transition emits an audit event (actor, prior mode, new
+   mode, precondition evidence reference including the configuration
+   acknowledgment) in the same transaction as the record change; the
+   event survives indefinitely. A refused attempt emits a refusal
+   event naming the failed precondition class and actor, with no
+   mode-change event.
+
+## 5. v1 obligations (non-foreclosure)
+
+v1 ships Standalone only (D11); the conversion command is deferred
+work. v1 still MUST:
+
+1. Record the mode per §2 at bootstrap, with `enterprise` a reserved,
+   refused value for bootstrap — v1 bootstrap accepts `standalone`
+   only. The wizard reads the record (contract 3 §2.3); nothing in v1
+   writes it after bootstrap.
+2. Keep the §2.3 immutability rule: no v1 surface mutates the mode
+   record.
+3. Not foreclose conversion: the v1 platform database holds no
+   sensitive user content — sensitive categories live in the owning
+   user's brain, and postgres holds structure, consent records, and
+   pointers only (the D14 boundary, PRD §7). Custody mechanics are
+   contract 7's; this contract binds the boundary itself here so v1
+   cannot ship a layout that makes the §4.2 brain precondition
+   unsatisfiable, and §6.3 gives it a stable witness that does not
+   depend on contract 7's internals. Conversion implementation
+   additionally requires contract 7 ratified.
+4. Not foreclose federation: v1 components accept exactly the two §1.1
+   values wherever a mode value is parsed and refuse any other value
+   **before side effects** — a refused configuration, not undefined
+   behavior and not a crash mid-operation. Forward compatibility lives
+   in storage and architecture, not in parser speculation: the mode
+   record's storage is not structurally locked to two values (no
+   database-level two-value enum), and any future value (e.g. a
+   federation mode) is defined by a versioned amendment to this
+   contract before any component accepts it. The PRD defers
+   federation's shape entirely; this contract does not presume it
+   arrives as a third mode value.
+
+## 6. Verification requirements
+
+Binding on the implementing PRs:
+
+1. **Mode-record witness (v1):** after bootstrap the mode is readable
+   via the Gateway command and CLI and equals the bootstrap-recorded
+   choice; bootstrap with mode `enterprise` is refused; bootstrap with
+   any unknown mode value is refused before side effects (§5.4).
+2. **Writer-coverage witness (v1):** the mode record's writer set is
+   closed by the same three-prong static assertion contract 1 §6.3(b)
+   defines — symbol, class-table literal, and raw-execution prongs
+   with its allowlist composition rules — scoped to the
+   `platform_mode` table, with a writer allowlist containing exactly
+   the bootstrap writer in v1 (and exactly plus the conversion command
+   at the conversion milestone). Companions: a crafted direct write
+   attempted in a test fails and leaves the record unchanged; a
+   mode-resolution assertion that no shipped component derives mode
+   from feature state (mode reads occur only through the §2.2 read
+   surface — static assertion over Gateway, CLI, bootstrap, and
+   repository sources).
+3. **D14-boundary witness (v1):** a column-allowlist assertion in the
+   style of contract 1 §6.2 that the platform database schema contains
+   no sensitive-content column — the §5.3 boundary — stable regardless
+   of contract 7's internals (contract 7 §7 carries the full custody
+   witnesses).
+4. **No-downgrade witness (conversion milestone):** with mode
+   `enterprise`, a conversion request to `standalone` (and any crafted
+   mode-write) is refused with the precondition/state error class and
+   no record change.
+5. **Precondition witnesses (conversion milestone),** each refused
+   with no record change and no partial mode effect, parameterized
+   over both OpenBao and Vault where secrets are involved:
+   (a) secrets backend unreachable; (b) one required secret still
+   flat-file backed (migration incomplete); (c) one unpartitioned user
+   brain in a **multi-user** deployment where every other user is
+   partitioned; (d) no active platform administrator (the only admin
+   banned or deactivated); (e) configuration acknowledgment missing or
+   mismatching the canonical registration/JIT values; (f) actor not a
+   platform administrator (authorization refusal); (g) irreversibility
+   acknowledgment absent. And the steady-state rule: an
+   Enterprise-mode component started against a flat-file secrets
+   configuration refuses to start (§3).
+6. **Interruption and fence witnesses (conversion milestone):** fault
+   injection aborting conversion after each preparation unit and
+   between preparation and flip leaves the record `standalone` and the
+   platform operational in Standalone semantics (§4.3
+   Standalone-safety), and a re-attempt completes without duplicating
+   prepared state (at-most-once keys); a precondition invalidated
+   after preparation but before the flip (a secret reverted to
+   flat-file) is caught by the in-transaction re-check and refused.
+7. **Audit witnesses (conversion milestone):** a completed conversion
+   has exactly one mode-change audit event, same-transaction with the
+   record change (transaction linkage asserted), carrying actor, prior
+   mode, new mode, and the precondition evidence reference including
+   the configuration acknowledgment; a failed attempt has a refusal
+   event naming the failed precondition class and no mode-change
+   event; the mode-change event remains queryable after subsequent
+   unrelated audit activity (retention probe).
+8. **Mapping witness (conversion milestone):** the conversion command
+   and the mode read command each have their
+   `tool-gateway-mapping.md` row (added by amendment per §2.2/§4.4)
+   before the commands ship.
+
+## Ruling request
+
+Ratify sections 1–6 as written, with one decision embedded:
+
+- Decision (§5): v1 implements the **mode record and its immutability
+  only** — bootstrap records `standalone`, the `enterprise` value is
+  reserved and refused, and the conversion command itself is deferred
+  to the Enterprise milestone, consistent with D11's deferred list.
+  v1 carries three obligations beyond the record: the closed writer
+  assertion, the D14 column boundary, and the unknown-value refusal
+  (§6.1–§6.3) — these are the non-foreclosure floor, not hidden
+  conversion work. Alternative if rejected: build the conversion
+  command inside v1 — rejected because D11 scopes v1 to the Standalone
+  slice and conversion depends on contract 7 custody mechanics that
+  are themselves not in the v1 slice.

docs/requirements/native-kanban-sot.md

@@ -456,3 +456,61 @@ this line is weakened.
 - Negative tests prove roll-up endpoints cannot mutate state and that a
   reader sees aggregates only over workspaces they are authorized on
   (no cross-tenant existence oracles).
+
+## 9. Amendment A2 — company visibility classes and the company directory
+
+**Status:** amendment to Amendment A1, added by reviewed PR under Ruling 4b
+(operator ruling, 2026-08-27; decision owner Jason; recorded in the webui-audit
+lane RULINGS.md). Everything in §§1–8 remains binding verbatim, with exactly
+the two express modifications below. Nothing else is weakened. The detailed
+contract text lives in the hierarchy schema contract
+(`hierarchy-schema.md` §2.8, §5.5, §6.9); this amendment changes only what A1
+itself permits, so that contract does not stretch A1 by interpretation.
+
+### 9.1 What A2 modifies in A1
+
+1. **Class data (extends §8.1.2's first constraint).** The tenancy/authorization
+   structure record class additionally carries **visibility-class data**: the
+   single column `companies.visibility`, values `private` | `directory`
+   (hierarchy schema §2.8). Visibility is disclosure data about the class's own
+   nodes — what a company row reveals about its own existence — and is part of
+   the class's tenancy/authorization purpose. It is not business or
+   orchestration payload. §8.1.2's payload prohibition is widened for nothing
+   else: hierarchy tables still MUST NOT carry task, plan, or any other
+   business/orchestration payload, and this amendment admits exactly this one
+   column.
+2. **The company directory (extends §8.1.3's function enumeration).** The
+   hierarchy serves one additional, express, narrow runtime function: the
+   **company directory** — a read-only disclosure listing of exactly the
+   companies whose `visibility = 'directory'`, revealing existence, name, and
+   slug to every authenticated user of the deployment and nothing else. It
+   mutates nothing, confers no authority, evaluates no grant down the chain,
+   and aggregates nothing (it is not a roll-up). §8.3's
+   no-cross-tenant-existence-oracle acceptance is narrowed by exactly this one
+   ratified carve-out: the directory is the sole permitted existence
+   disclosure, and it discloses only directory-class companies (witnessed in
+   hierarchy schema §6.7 and §6.9). Private companies remain undisclosed to
+   non-granted subjects everywhere, including the directory.
+
+### 9.2 What A2 explicitly does not change
+
+1. Content access stays grant-only under the RBAC grant model contract:
+   directory listing discloses existence, never content, membership, or any
+   authority (Ruling 3 unchanged; hierarchy schema §2.8).
+2. **No join-request surface is authorized.** Ruling 4b decision 5's
+   see-and-ask-to-join flow is a follow-up contract in its entirety —
+   including the ability to submit a request. A2 admits exactly the
+   read-only listing of §9.1.2 and nothing more; hierarchy schema §2.8
+   states the invariants that pre-bind the future flow contract, and that
+   contract must itself amend this enumeration before any join-request
+   runtime surface exists.
+3. Visibility changes are hierarchy mutations on the existing §8.2.3 audited
+   mutation path — audited maintenance of the class's own structure in
+   §8.1.3's sense, not a further runtime function. Authorization for them is
+   defined in hierarchy schema §5.5 (platform admins plus the future
+   company-CRUD capability; owner-as-such cannot publish).
+4. Company creation is unchanged and always yields `visibility = 'private'`
+   (onboarding wizard §5.2); this amendment adds no creation path and no
+   default-open disclosure.
+5. Every other constraint of A1 — §8.1.2's remaining bullets, §8.2 in full,
+   and §8.3's other acceptance criteria — is untouched.

docs/requirements/onboarding-wizard.md

@@ -397,6 +397,14 @@ seed-workspace-scoped mutant, correctly refusing outside the seed
 set, passes branch (c), so the two branches detect distinct
 mutants. No other change.
 
+Amendment 1 (Ruling 4b, 2026-08-28): §5.2's embedded decision was RULED
+AGREED (Jason, 2026-08-27), and Ruling 4b adds company visibility
+classes (hierarchy schema §2.8): open top-level creation always yields
+a **private** company; publishing a company into the deployment-wide
+directory is a separate, gated visibility mutation (hierarchy schema
+§5.5) that is never part of the creation command. §5.2 is amended to
+state both.
+
 Scope: the Gateway-backed product onboarding wizard. Out of scope: the
 host-local install wizard (`mosaic wizard`, which drives host install and
 gateway bootstrap and is not this artifact — audit REPORT.md layer 3);
@@ -1169,15 +1177,18 @@ collects no sensitive category, so v1 ships no custody surface.
    party, service actor, or wizard-privileged writer exists in this
    flow.
 2. **Post-bootstrap top-level company creation** — the "N companies" flow
-   — is decided by the ruling below: any **eligible platform user** MAY
+   — RULED AGREED (Jason, 2026-08-27): any **eligible platform user** MAY
    create a top-level company and MUST name an initial `owner` grant in
    the same audited operation (contract 2 §4.3); the creator naming
    themselves is the default. Eligible means, in identity-contract
    terms: an authenticated account (identity §2) that is not banned
    (identity §7.1 — deactivation on this platform IS the better-auth
    ban; no separate deactivated state exists). No further role or grant
-   is required. Until that ruling, deny-by-default holds (contract 2
-   §3.1): no implicit creation authority exists.
+   is required. Creation always yields a **private** company
+   (`visibility = 'private'`, hierarchy schema §2.8, Ruling 4b): the
+   creation command accepts no visibility argument, and publishing into
+   the deployment-wide directory is a separate, gated mutation
+   (hierarchy schema §5.5) that standard users cannot perform.
 3. Child-node creation inside the wizard (estate, project, workspace
    under the seeded company) follows contract 2 §4.3: parent
    `owner` authority, no automatic grant needed — for canonical seed
@@ -1932,7 +1943,13 @@ contracts and are not additions:
     suffix at all — each contradicting PRD D4's no-lock-in
     requirement (§4.4).
 
-## Ruling request
+## Ruling request — RULED AGREED (Jason, 2026-08-27; Amendment 1)
+
+The §5.2 decision below was ruled agreed: open eligible-user creation
+stands (yielding private companies per Amendment 1), and the
+"alternative if rejected" did not take effect. The request is retained
+below as historical record of what was put to ruling; it is no longer
+live.
 
 Ratify sections 1–7 as written, with one decision embedded:
 

docs/requirements/rbac-grant-model.md

@@ -0,0 +1,259 @@
+# RBAC Grant Model Contract
+
+Status: DRAFT — awaiting ratification (webui-audit S2, contract 2 of 9).
+Authority: PRD Part I §4 ("Granular RBAC: admins restrict access per company,
+estate, and project; grants are evaluated down the chain") and the
+native-kanban SOT Amendment A1 (§8.1.3 RBAC evaluation, §8.3 acceptance 2).
+This document defines the grant vocabulary, evaluation semantics, and
+revocation propagation that the hierarchy schema contract
+(`docs/requirements/hierarchy-schema.md`, contract 1) attaches to. Contract 1
+pins the `hierarchy_grants` table shape and defers the `role` vocabulary and
+the meaning of "authority" here; the identity contract
+(`docs/requirements/identity-lifecycle.md` §1.4) pins that account creation
+grants nothing.
+
+Revision 2 (independent review, GLM 5.3): §1.1 consequence analysis
+completed — the two existing platform-admin bypass code paths are named as
+non-conformant and §7.4 retires them; team grant subjects suspended pending
+a team contract (§1.4, §3.3–3.4, §7.5); no-self-escalation restated with
+its true rationale and a constructible observable (§4.2, §7.7);
+node-creation seeding scoped to the bootstrap path, resolving the §7.7/§4.3
+contradiction; A1 quotation corrected; audit-field provenance corrected;
+principal-position consequence named (§1.3); membership-row,
+fail-closed-fault, and existence-oracle observables added (§7);
+role-string namespacing rule added (§4.5); ruling request now names the
+interpretive resolution of PRD "admins".
+
+Scope: the roles that can appear in `hierarchy_grants.role`, what a grant at
+each hierarchy level confers, how grants evaluate down the chain, how
+revocation propagates, and who may manage grants. Out of scope: the hierarchy
+tables themselves (contract 1), workspace-internal membership and its
+role/capability vocabulary (native-kanban SOT REQ-ID-001 and its implementing
+schema), roll-up projection semantics (contract 8), wizard seeding
+(contract 3), the team model (suspended here; see §1.4).
+
+## 1. Three authority layers, none substitutable
+
+1. **Platform role** (`users.role`, better-auth: `member` | `admin`) governs
+   instance administration — user management, system settings, provider
+   configuration. It is not tenancy authority: holding platform `admin`
+   confers **no implicit hierarchy grant and no workspace authorization**.
+   An operator who should see tenant content holds an explicit, audited
+   grant like anyone else. This is the deny-by-default consequence of A1
+   §8.1.3 ("not a bypass of workspace authorization"). `AdminGuard`'s
+   `role === 'admin'` check on admin endpoints stays the platform role's
+   only meaning. **Two shipped code paths violate this rule today and are
+   implementation defects this contract makes non-conformant:** (a) the
+   command authorization service short-circuits every command scope to
+   allowed for platform admins
+   (`apps/gateway/src/commands/command-authorization.service.ts`,
+   `hasScope` returning true when `role === 'admin'`), and (b) the MCP
+   scope derivation maps platform `admin` to tenant-admin MCP scopes
+   including task create/update
+   (`apps/gateway/src/mcp/mcp.service.ts`,
+   `deriveMcpToolScopesForUser`). Ratifying this contract revokes both;
+   §7.4 names them as the surfaces the deny-by-default test retires.
+2. **Hierarchy grants** (`hierarchy_grants`, contract 1 §3) declare tenancy
+   authority at company, estate, or platform-project scope and evaluate down
+   the chain to workspace-scoped authorization (§3 below).
+3. **Workspace membership** (SOT REQ-ID-001) remains its own mechanism.
+   A chain grant confers command authorization over descendant workspaces;
+   it does not create membership rows, and row-level principal positions
+   (task owner, proposer, decision actor) still require ACTIVE workspace
+   membership exactly as REQ-TEN-001/REQ-ID-001 acceptance states.
+   Consequence, stated so implementing PRs do not weaken REQ-TEN-001 to
+   remove the friction: a chain-granted actor who is not a workspace member
+   may issue the write commands their role implies but cannot occupy a
+   principal position — any command taking a principal argument must name
+   an ACTIVE member of the target workspace (§7.2 enumerates this cell).
+4. **Team grant subjects are suspended.** Contract 1 §3.1 reserves a
+   `team_id` attachment point, but no ratified contract yet defines the
+   team it would bind: the only existing `teams` table is the legacy global
+   Brain table (own authority columns, no workspace binding, not
+   repurposed per contract 1 §1.3), while the SOT's teams are
+   workspace-bound (REQ-ID-001) — and a workspace-bound team holding a
+   company-level grant would be a cross-workspace authority group nothing
+   has ratified. Until a team contract defines the subject (which table,
+   which membership rows, and its relation to D2/REQ-ID-001), creating a
+   grant with a team subject MUST be refused at the command surface (the
+   schema column remains, per contract 1). §3's evaluation semantics for
+   team-conferred grants are specified now so the team contract activates
+   them without amending this one.
+
+## 2. Role vocabulary
+
+One vocabulary at every hierarchy level, totally ordered — a higher role
+includes everything below it:
+
+1. `viewer` — read: sees the node, its subtree structure, and the roll-up
+   aggregates over descendant workspaces (within contract 8's carve-out
+   bounds); read access to descendant workspace content per the SOT's read
+   command families. No mutation of anything.
+2. `member` — work: everything `viewer` has, plus write authorization for
+   business/orchestration command families in descendant workspaces (the
+   concrete command-family mapping is implementation work under SOT
+   REQ-ID-001; this contract pins that `member` maps to the workspace write
+   families and nothing structural).
+3. `owner` — structure: everything `member` has, plus hierarchy mutations on
+   the subtree (create/rename/delete child nodes, transfers per §5), and
+   grant management on the node and its subtree (§4).
+
+No other value is valid in `hierarchy_grants.role`; the column is
+constraint-checked against exactly these three. Extending the vocabulary is a
+contract amendment, not an implementation decision.
+
+## 3. Evaluation semantics
+
+1. **Deny by default.** No grant on any ancestor → no authority. There are
+   no implicit grants: not from platform role (§1.1), not from creating a
+   node (§4.3), not from workspace membership (membership without a chain
+   grant confers exactly what the SOT's own membership rules confer inside
+   that workspace, nothing up the chain).
+2. **Down-the-chain only.** A grant on a node applies to that node and its
+   entire descendant subtree. Nothing evaluates upward or sideways: a grant
+   on an estate says nothing about the parent company or sibling estates.
+3. **Effective role = maximum.** A subject's effective role at any node is
+   the highest role among grants held directly by the subject's user on
+   that node or any ancestor — and, once the team contract activates team
+   subjects (§1.4), grants held by any team the user is a member of on that
+   node or any ancestor. Roles never subtract — there is no negative/deny
+   grant in this model; revocation is deletion (§6).
+4. **Team grants follow live membership** (specified now, active only per
+   §1.4). A team grant confers its role on the team's current members,
+   evaluated at decision time. Leaving the team is loss of the grant with
+   §6's propagation bound.
+5. **Live evaluation, fail closed.** Authorization decisions derive from the
+   live grant and team-membership rows (or from a cache that is invalidated
+   in the same transaction as any grant/membership/hierarchy mutation). A
+   decision path that cannot read grant state denies. No materialized ACL is
+   ever authoritative.
+6. **Tenant context stays derived from authenticated authority**
+   (REQ-TEN-001). The chain adds where grants can be declared; a workspace
+   request is still authorized against that workspace, with the chain
+   contributing the effective role — never letting the chain become what A1
+   §8.1.3 forbids: "a bypass of workspace authorization".
+
+## 4. Grant management
+
+1. Creating, changing, or revoking a grant on a node requires effective
+   `owner` on that node (directly or via any ancestor).
+2. **No self-escalation.** A grant manager cannot create a grant with a role
+   higher than their own effective role on the target node. Under the §2
+   vocabulary this rule is currently implied by §4.1 (managers are `owner`,
+   the top role — no constructible grant exceeds it); it is stated
+   explicitly so it survives any future amendment that decouples
+   grant-management authority from role height. Its observable is the §7.7
+   audit invariant, not a refusal test.
+3. **Bootstrap of authority is explicit; inheritance covers the rest.**
+   Creating the first company (the wizard path, contract 3) and any
+   top-level company creation MUST name the initial `owner` grant in the
+   same audited operation — a top-level node has no ancestor to inherit
+   from, so without this the node would be unownable. Creating a child node
+   (estate, platform-project, workspace) requires effective `owner` on the
+   parent (§2.3) and confers no automatic grant; the creator's authority
+   over the new node already follows from §3.2 down-the-chain evaluation.
+   The creating command MAY additionally name an explicit initial grant for
+   a child node; it is not required to.
+4. Every grant mutation is a semantic audit event under contract 1 §5.2's
+   guarantees, extended by this contract with two further fields: the event
+   carries actor, verb, target, **subject, and role** (subject and role are
+   this contract's addition; contract 1 §5.2 does not enumerate them).
+5. **Role strings are namespaced.** `viewer`/`member` exist at hierarchy
+   level, `member`/`admin` on `users.role`, and the current command layer
+   uses a third `viewer|member|admin` vocabulary — same strings, different
+   meanings. Any serialized role string (audit events per §4.4, API
+   responses, logs) MUST identify its layer (e.g. `hierarchy:owner`,
+   `platform:admin`); a bare role string in a serialized artifact is
+   non-conformant.
+
+## 5. Transfer authority (completes contract 1 §4.2)
+
+"Authority over BOTH the source and the destination parent" means: effective
+`owner` on the current parent node (or an ancestor) AND effective `owner` on
+the destination parent node (or an ancestor), evaluated at transfer time in
+the transfer's own transaction. One subject must hold both; two cooperating
+half-authorized subjects are not a transfer protocol this contract defines.
+
+## 6. Revocation propagation
+
+1. Revoking a grant (deleting the row), removing a user from a team that
+   carries a grant (once team subjects activate, §1.4), or the cascade
+   deletion of a node's grants during node deletion (contract 1 §3.3) all
+   propagate identically: the authority derived from that grant is gone for
+   every descendant workspace.
+2. **Bound:** the next authorization decision on any affected transport
+   decides against the revoked grant. Concretely: no new HTTP/MCP command
+   authorized by the revoked grant after the revoking transaction commits;
+   an open Socket.IO connection whose subscriptions depend on the revoked
+   grant is re-evaluated within 30 seconds or at its next inbound message,
+   whichever comes first (same bound as the identity contract's §7.1
+   deactivation rule; same mechanism may serve both).
+3. Revocation is subtractive only in effect, not in representation: the
+   evaluator never needs tombstones; deletion of the row is the revocation.
+
+## 7. Verification requirements
+
+Binding on the implementing PRs (extends A1 §8.3 acceptance 2–3 and
+contract 1 §6):
+
+1. Vocabulary: the role CHECK constraint rejects any value outside
+   `viewer|member|owner` (real-PostgreSQL witness, `ci-postgres` service in
+   the `test` CI step).
+2. Per-level conferral: for each of the three levels × three roles, a grant
+   yields exactly the implied workspace authorization in a descendant
+   workspace and nothing in a non-descendant workspace (the A1 §8.3
+   "exactly the permissions the chain implies" matrix, enumerated). The
+   matrix includes: a chain grant creates zero workspace-membership rows
+   (assert row counts); a chain-granted non-member is refused as the
+   principal argument of any principal-taking command while their
+   non-principal writes succeed (§1.3); structure reads leak no existence
+   of nodes the reader holds no grant on (no cross-tenant existence
+   oracle, A1 §8.3 acceptance 3).
+3. Ordering: `owner` ⊇ `member` ⊇ `viewer` behaviorally — each higher role
+   passes every lower role's positive cases.
+4. Deny-by-default: platform `admin` with no grant reaches no tenant
+   content — asserted against the two §1.1 non-conformant surfaces after
+   their retirement: the command-authorization admin short-circuit and the
+   MCP tenant-admin scope derivation both gone (a platform admin with no
+   grant is refused workspace commands and receives no tenant MCP scopes);
+   workspace member with no chain grant gains nothing outside SOT
+   membership semantics; fresh account reaches nothing (identity contract
+   §1.4 cross-check).
+5. Team subjects: while suspended (§1.4), creating a team-subject grant is
+   refused at the command surface. On activation by the team contract:
+   user-direct and team-conferred grants combine to the maximum; team-leave
+   drops authority within the §6.2 bound; decision-time evaluation
+   witnessed (grant added → next decision allows; no restart or re-login
+   required).
+6. Revocation: each revocation path in §6.1 denies the next command on
+   every transport; the socket bound is measured; a cached-authorization
+   implementation proves transactional invalidation (grant revoked and
+   decision made on two distinct physical connections). Fail-closed fault
+   witness for §3.5: with grant state unreadable (fault injection), the
+   decision denies.
+7. Grant management: non-`owner` cannot mutate grants; top-level company
+   creation without the named initial `owner` grant is refused, while child
+   node creation under ancestor authority succeeds without one (§4.3 both
+   directions); every mutation produces its audit event with the §4.4
+   fields. Self-escalation observable: over the audit event stream, every
+   grant-create/change event's role is ≤ the acting user's effective role
+   on the target at event time (reconstructable invariant, not a refusal
+   test — see §4.2).
+8. Transfer: both-sides `owner` accepted, each single-side case refused
+   (completing contract 1 §6.5).
+
+## Ruling request
+
+Ratify sections 1–7 as written, with one decision embedded and one
+interpretive resolution named:
+
+- Decision: platform `admin` confers no implicit tenant access — operators
+  see tenant content only through explicit, audited grants (§1.1), which
+  retires the two existing admin bypass paths named there. Say "agreed" or
+  name the implicit access you want platform admins to keep.
+- Interpretive resolution (for visibility, not a separate question): PRD
+  Part I §4 says "admins restrict access per company, estate, and project";
+  this contract resolves "admins" as hierarchy `owner`s (§4.1), not
+  platform admins. A1 §8.1.3 does not attribute grant declaration to
+  platform admins, and the §1.1 decision above is what makes this reading
+  binding.

docs/requirements/tool-gateway-mapping.md

@@ -0,0 +1,197 @@
+# Tool↔Gateway Mapping Contract (D8)
+
+Status: DRAFT — awaiting ratification (webui-audit S2, contract 5 of 9).
+Authority: PRD D8/D12 (Part I §8) — the webUI sits OVER official tooling:
+every webUI operation goes through the Gateway API backed by the same
+official framework tooling the CLI uses, and a webUI operation with no
+backing tool is scored **blocked on tooling** and the tool is built
+first. Measured input: the webui-audit A5 tooling baseline
+(operation-by-operation inventory of the current Gateway surface and the
+P1 gaps, cross-reviewed; `fleet/lanes/webui-audit/findings/
+A5-tooling-baseline.md` in the estate brain). The T10 ruling adopted the
+targeted-update plan including building the D8 tools in A5's rank order.
+
+Revision 2 (GLM review F1–F5): the §2 table completed against an
+independent re-measurement of the live `apps/web` surface (mission
+reads, coordination status, capability-gated `turn:send` added); rank-6
+composition corrected to ranks 1 and 4; SOT citations corrected to §3
+invariant 11 / REQ-TASK-001 / §5+A1; the §3.2 retirement clause
+softened to match what the owning contracts actually schedule; §6.1
+scoped to outbound calls with an extractability lint, and §6.3 given
+static companions for §4.1 and §4.3.
+
+This contract binds three things: the operation→tool mapping itself
+(§2–§3), the command envelope every mapped operation satisfies
+(§4), and the process rule that keeps the mapping closed (§5). Domain
+semantics stay with their owning contracts — hierarchy (contract 1,
+`hierarchy-schema.md`), grants (contract 2, `rbac-grant-model.md`),
+wizard (contract 3, `onboarding-wizard.md`), identity
+(`identity-lifecycle.md`), kanban lifecycle (`native-kanban-sot.md`
+§5 and Amendment A1), roll-up (contract 8), API artifact format
+(contract 9).
+
+## 1. Definitions
+
+1. **Official tool**: a command implemented in the framework packages and
+   exposed through the Gateway API; the CLI remains the primary execution
+   method for the same command (D8). The webUI is a Gateway client only.
+2. **Mapped operation**: a webUI operation with a named official path in
+   §2 or §3. Anything else the webUI wants to do is unmapped and follows
+   §5.
+3. **Legacy non-substitute**: an existing endpoint that resembles a P1
+   need but is contractually barred from backing it (§3.2).
+
+## 2. P0 mapping (current operations, ratified as-is)
+
+This table is the complete measured P0 surface: every Gateway call the
+web app's production sources make at this revision's head appears as a
+row (independently re-measured at review; the three calls the first
+measurement missed — mission reads, coordination status, and the
+capability-gated `turn:send` emit — are rows below). The surface stays
+bound to these paths:
+
+| WebUI operation                                                   | Official path                                                                                                                                                                                                                               |
+| ----------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| Register / log in / log out / OIDC callback                       | better-auth mount `/api/auth/*`; `GET /api/sso/providers`                                                                                                                                                                                   |
+| List/show projects (legacy read)                                  | `GET /api/projects`, `GET /api/projects/:id`                                                                                                                                                                                                |
+| List tasks / task detail (legacy read)                            | `GET /api/tasks`, `GET /api/tasks/:id` — with the filtered legacy project/mission reads the same surfaces use                                                                                                                               |
+| Mission list (legacy read)                                        | `GET /api/missions`                                                                                                                                                                                                                         |
+| Coordination status (legacy read)                                 | `GET /api/coord/status`                                                                                                                                                                                                                     |
+| Conversation CRUD/search/messages                                 | `/api/conversations*`                                                                                                                                                                                                                       |
+| Chat turn / stop / thinking / command execute+approve / streaming | `/chat` socket events `message`, `abort`, `set:thinking`, `command:execute`, `command:approve`; `turn:send` (capability-gated — emitted only when the server advertises the pi turn-runtime capability, which the current Gateway does not) |
+| Harness/model selection                                           | `GET /api/harnesses*`, `GET/PUT /api/chat/preferences/selection`                                                                                                                                                                            |
+| Preferences; provider inspect/test                                | `/api/memory/preferences`, `GET /api/providers`, `POST /api/providers/test`                                                                                                                                                                 |
+| Admin users / roles / ban / health                                | `/api/admin/users*`, `/api/admin/health`                                                                                                                                                                                                    |
+
+P0 rows inherit §4 obligations as their backing controllers are next
+touched; they are not required to be retrofitted in one sweep.
+
+## 3. P1 mapping (bound to the build-first tools)
+
+1. Every P1 operation maps to exactly one build-first command family, in
+   the T10-ruled rank order:
+
+| Rank | Command family (owning contract)                                       | P1 webUI operations it backs                                                                                                                      |
+| ---- | ---------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
+| 1    | Hierarchy command family (contract 1 §5; grants attach per contract 2) | Company/estate/platform-project/workspace CRUD, parentage and reparenting, hierarchy reads; the wizard's initial-hierarchy step (contract 3 §3.4) |
+| 2    | Hierarchy RBAC command/evaluator (contract 2)                          | Grant create/change/revoke at company/estate/platform-project; inherited evaluation down to workspace; authorization-safe hierarchy queries       |
+| 3    | Typed kanban command/query surface (SOT §5, Amendment A1)              | Workspace task lifecycle (create/edit/cancel/archive/move), board rank, typed queries                                                             |
+| 4    | Agent enrollment command                                               | Enroll one agent: harness, credential reference/API-key intake (values never echoed), name/persona, assignment scope (contract 3 §3.5)            |
+| 5    | Authorized roll-up query (contract 8)                                  | Read-only aggregated task counts/statuses at every hierarchy level over readable workspaces only                                                  |
+| 6    | Onboarding orchestration (contract 3)                                  | The re-runnable wizard flow, composing ranks 1 and 4 (its only grant write rides inside the rank-1 company-create command, contract 2 §4.3)       |
+
+2. **Legacy non-substitutes.** The following MUST NOT back any P1
+   operation, matching the audit findings: legacy `/api/projects` and
+   `/api/tasks` CRUD (planning-data records, not hierarchy nodes and not
+   the typed kanban boundary); `POST /api/workspaces` (filesystem
+   bootstrap, not audited hierarchy parentage); `/api/teams` reads (no
+   grants, no inheritance); `POST /api/bootstrap/setup` (one-shot
+   epoch transition, identity §3 — not the re-runnable wizard); the MCP
+   `brain_*` task mutations (legacy Brain writes, not the typed kanban
+   commands). These stay serving their existing P0/host consumers until
+   the owning contract (or a successor amendment) schedules each
+   retirement — no such migration is scheduled at this revision; the
+   freeze stands on its own.
+3. New P1 mapping rows (operations this table does not list) are added by
+   amending this contract, not ad hoc (§5).
+
+## 4. Command envelope (request / result / error / audit)
+
+Binding on every mapped operation the build-first families expose:
+
+1. **Typed request and result.** Each command and query has an explicit
+   request DTO and result DTO in the shared types package, validated at
+   the Gateway boundary; unvalidated pass-through and `any`-typed
+   payloads are non-conformant. Mutations on records with an
+   expected-version rule in their owning contract carry the expected
+   version in the request and fail on mismatch with the conflict error
+   class (SOT §3 invariant 11 and REQ-TASK-001's concurrent-update
+   conflict acceptance; hierarchy per contract 1).
+2. **Error taxonomy.** Every error result carries a stable
+   machine-readable code from a closed per-family enum plus an HTTP
+   status mapping, distinguishing at minimum: validation failure,
+   authentication failure, authorization refusal, not-found, conflict
+   (version/uniqueness), precondition/state refusal (e.g. bootstrap
+   epoch, suspended team subjects), and internal fault. Where contract
+   2's no-existence-oracle rule applies, authorization refusal and
+   not-found are indistinguishable on the wire for unauthorized readers
+   — same code, same status, same shape.
+3. **Audit linkage.** A mutating mapped operation emits exactly the
+   audit events its owning contract defines (contract 1 §5.2, contract 2
+   §4.4, identity §§2–4, SOT audit rules); the envelope contributes the
+   correlation: every request accepts/generates a correlation id,
+   carried into the audit events and returned in the result, so a UI
+   action is traceable end to end. The mapping layer itself adds no
+   second audit stream.
+4. **Fail-closed.** A mapped operation that cannot evaluate its
+   authorization or reach its owning tool refuses (contract 2 §3.5); the
+   envelope never degrades to an unauthorized fallback read or a direct
+   data access.
+5. **CLI parity.** Each build-first family is invocable through the
+   official CLI against the same Gateway commands with the same
+   request/result/error contracts. No webUI-only command exists; a
+   Gateway command without CLI exposure is a conformance gap tracked at
+   the family's implementing issue.
+
+## 5. Closure rule (blocked on tooling)
+
+1. A webUI change that needs an operation with no mapping row is
+   **blocked on tooling**: the backing tool is built and mapped first
+   (D8). Scoring a gap "blocked on tooling" is mandatory, not
+   discretionary; working around it in the UI (direct DB or filesystem
+   access, calling a legacy non-substitute, embedding domain logic in
+   the web app) is non-conformant.
+2. The mapping is enforced closed by §6.1's inventory witness: the web
+   app's network surface must be a subset of the mapped paths.
+
+## 6. Verification requirements
+
+Binding on the implementing PRs:
+
+1. **Network-surface inventory witness:** a CI assertion extracting the
+   web app's outbound Gateway calls — route literals at request call
+   sites and outbound socket emits in `apps/web` sources (inbound
+   handler registrations are not calls and are out of scope) — and
+   failing on any call outside the §2/§3 mapped paths. The inventory is
+   closed like contract 1 §6.3's allowlist: a new call fails until a
+   mapping row exists in the same PR. Dynamic route construction that
+   evades extraction is resolved toward the witness, enforced by an
+   extractability lint: every request call site takes a literal or
+   template-literal path, and a call site that does not fails the
+   assertion itself (the web-side analogue of contract 1's
+   raw-execution prong), never an exemption for the caller.
+2. **Non-substitute witness:** the P1 surfaces (hierarchy, RBAC, kanban,
+   enrollment, roll-up, wizard UI) make zero calls to the §3.2 legacy
+   endpoints — asserted by the same inventory, scoped per surface.
+3. **Envelope witnesses per family:** for each build-first family — a
+   request with an invalid DTO is refused with the validation code; a
+   version-mismatch mutation returns the conflict code; an unauthorized
+   read of an existing node and a read of a nonexistent node return
+   indistinguishable results where the no-existence-oracle rule applies;
+   a correlation id submitted on a mutation appears in its audit
+   event(s) and result. Two static companions: a type-level assertion
+   that the family's boundary accepts no `any`-typed or unvalidated
+   pass-through payload (§4.1), and a single-emitter assertion that the
+   mapped operation's audit events originate only from the owning
+   contract's audit emitter (§4.3's no-second-audit-stream, made
+   checkable).
+4. **CLI-parity witness:** for each family, a CLI smoke invocation of at
+   least one command and one query against the Gateway succeeds with the
+   same typed result the web client receives.
+5. **Fail-closed witness:** with the owning tool or grant state
+   unreachable (fault injection), the mapped operation returns the
+   internal-fault or authorization-refusal class and performs no
+   fallback read/write (extends contract 2 §7.6 to the mapping layer).
+
+## Ruling request
+
+Ratify sections 1–6 as written, with one decision embedded:
+
+- Decision (§3.2): the legacy endpoints named there are **frozen for new
+  consumers** as of ratification — existing P0/host consumers keep
+  working, new UI or tool code may not call them, and each is retired by
+  the migration its owning contract schedules. Alternative if rejected:
+  allow P1 surfaces to reuse legacy endpoints as interim backends —
+  rejected by the audit's finding that they cannot satisfy the
+  hierarchy/kanban/RBAC contracts, so the interim would ship
+  non-conformant semantics.

packages/db/drizzle/0019_volatile_killraven.sql

@@ -0,0 +1,40 @@
+CREATE TYPE "public"."hierarchy_outbox_status" AS ENUM('pending', 'processing', 'delivered');--> statement-breakpoint
+CREATE TABLE "hierarchy_audit_events" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"seq" bigint GENERATED ALWAYS AS IDENTITY (sequence name "hierarchy_audit_events_seq_seq" INCREMENT BY 1 MINVALUE 1 MAXVALUE 9223372036854775807 START WITH 1 CACHE 1),
+	"actor_id" text NOT NULL,
+	"verb" text NOT NULL,
+	"target_kind" text NOT NULL,
+	"target_id" uuid NOT NULL,
+	"target_snapshot" jsonb NOT NULL,
+	"transfer_from" jsonb,
+	"transfer_to" jsonb,
+	"correlation_id" text NOT NULL,
+	"causation_id" uuid,
+	"idempotency_key" text NOT NULL,
+	"occurred_at" timestamp with time zone DEFAULT now() NOT NULL,
+	CONSTRAINT "hierarchy_audit_events_verb_check" CHECK (verb IN ('create', 'rename', 'transfer', 'delete', 'grant_create', 'grant_change', 'grant_revoke')),
+	CONSTRAINT "hierarchy_audit_events_target_kind_check" CHECK (target_kind IN ('company', 'estate', 'platform_project', 'grant')),
+	CONSTRAINT "hierarchy_audit_events_transfer_check" CHECK ((verb = 'transfer') = (transfer_from IS NOT NULL AND transfer_to IS NOT NULL))
+);
+--> statement-breakpoint
+CREATE TABLE "hierarchy_outbox" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"event_id" uuid NOT NULL,
+	"idempotency_key" text NOT NULL,
+	"correlation_id" text NOT NULL,
+	"status" "hierarchy_outbox_status" DEFAULT 'pending' NOT NULL,
+	"created_at" timestamp with time zone DEFAULT now() NOT NULL,
+	"updated_at" timestamp with time zone DEFAULT now() NOT NULL,
+	"delivered_at" timestamp with time zone
+);
+--> statement-breakpoint
+ALTER TABLE "hierarchy_audit_events" ADD CONSTRAINT "hierarchy_audit_events_causation_id_hierarchy_audit_events_id_fk" FOREIGN KEY ("causation_id") REFERENCES "public"."hierarchy_audit_events"("id") ON DELETE restrict ON UPDATE no action;--> statement-breakpoint
+ALTER TABLE "hierarchy_outbox" ADD CONSTRAINT "hierarchy_outbox_event_id_hierarchy_audit_events_id_fk" FOREIGN KEY ("event_id") REFERENCES "public"."hierarchy_audit_events"("id") ON DELETE restrict ON UPDATE no action;--> statement-breakpoint
+CREATE UNIQUE INDEX "hierarchy_audit_events_idempotency_idx" ON "hierarchy_audit_events" USING btree ("idempotency_key");--> statement-breakpoint
+CREATE UNIQUE INDEX "hierarchy_audit_events_seq_idx" ON "hierarchy_audit_events" USING btree ("seq");--> statement-breakpoint
+CREATE INDEX "hierarchy_audit_events_target_seq_idx" ON "hierarchy_audit_events" USING btree ("target_id","seq");--> statement-breakpoint
+CREATE INDEX "hierarchy_audit_events_correlation_idx" ON "hierarchy_audit_events" USING btree ("correlation_id");--> statement-breakpoint
+CREATE UNIQUE INDEX "hierarchy_outbox_event_idx" ON "hierarchy_outbox" USING btree ("event_id");--> statement-breakpoint
+CREATE UNIQUE INDEX "hierarchy_outbox_idempotency_idx" ON "hierarchy_outbox" USING btree ("idempotency_key");--> statement-breakpoint
+CREATE INDEX "hierarchy_outbox_status_created_idx" ON "hierarchy_outbox" USING btree ("status","created_at");

packages/db/drizzle/0020_special_betty_brant.sql

@@ -0,0 +1,5 @@
+ALTER TABLE "hierarchy_audit_events" DROP CONSTRAINT "hierarchy_audit_events_verb_check";--> statement-breakpoint
+ALTER TABLE "companies" ADD COLUMN "visibility" text DEFAULT 'private' NOT NULL;--> statement-breakpoint
+ALTER TABLE "companies" ADD CONSTRAINT "companies_visibility_check" CHECK (visibility IN ('private', 'directory'));--> statement-breakpoint
+ALTER TABLE "hierarchy_audit_events" ADD CONSTRAINT "hierarchy_audit_events_verb_check" CHECK (verb IN ('create', 'rename', 'transfer', 'visibility_change', 'delete', 'grant_create', 'grant_change', 'grant_revoke'));--> statement-breakpoint
+ALTER TABLE "hierarchy_grants" ADD CONSTRAINT "hierarchy_grants_role_check" CHECK (role IN ('viewer', 'member', 'owner'));

packages/db/drizzle/meta/_journal.json

@@ -134,6 +134,20 @@
       "when": 1787862158838,
       "tag": "0018_clean_cobalt_man",
       "breakpoints": true
+    },
+    {
+      "idx": 19,
+      "version": "7",
+      "when": 1787880918208,
+      "tag": "0019_volatile_killraven",
+      "breakpoints": true
+    },
+    {
+      "idx": 20,
+      "version": "7",
+      "when": 1787963521142,
+      "tag": "0020_special_betty_brant",
+      "breakpoints": true
     }
   ]
 }

packages/db/src/hierarchy-audit.witness.test.ts

@@ -0,0 +1,363 @@
+/**
+ * Hierarchy audit event + outbox schema witnesses — contract 1 §5.2 and the
+ * schema-level half of §6.4.
+ *
+ * Witnesses the guarantees the tables themselves carry: verb/target-kind/
+ * transfer CHECK constraints, idempotency uniqueness (REQ-AUD-001 duplicate
+ * suppression at the database level), monotonic append order (`seq`),
+ * deletion-safe linkage (no foreign key from the events table into any class
+ * table — events survive the deletion of their target), the causation
+ * self-FK, and the outbox's FK/uniqueness/status shape. The repository-level
+ * half of §6.4 (same-transaction atomicity, rollback, replay) is witnessed in
+ * apps/gateway/src/hierarchy/hierarchy-audit.integration.test.ts.
+ *
+ * Two legs run the same witness body:
+ *  - PGlite (WASM Postgres): always runs.
+ *  - Real PostgreSQL (§6.8): runs when DATABASE_URL is set — the binding
+ *    witness; CI migrates ci-postgres before `pnpm test`.
+ */
+import { randomUUID } from 'node:crypto';
+import { mkdtempSync, rmSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { sql } from 'drizzle-orm';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { createDb } from './client.js';
+import { createPgliteDb } from './client-pglite.js';
+import { runPgliteMigrations } from './migrate.js';
+import { companies, hierarchyAuditEvents, hierarchyOutbox } from './schema.js';
+
+type AnyDb = {
+  db: {
+    insert: (t: unknown) => { values: (v: unknown) => Promise<unknown> };
+    execute: (q: unknown) => Promise<{ rows?: unknown[] } | unknown[]>;
+  };
+  close: () => Promise<void>;
+};
+
+/** Match a constraint failure anywhere along drizzle's cause chain. */
+async function expectViolation(p: Promise<unknown>, re: RegExp, label = ''): Promise<void> {
+  let err: unknown;
+  try {
+    await p;
+  } catch (e) {
+    err = e;
+  }
+  expect(err, label || 'expected the statement to be refused').toBeDefined();
+  const messages: string[] = [];
+  let cur: unknown = err;
+  while (cur instanceof Error) {
+    messages.push(cur.message);
+    cur = (cur as { cause?: unknown }).cause;
+  }
+  expect(messages.join(' | '), label).toMatch(re);
+}
+
+function rows(res: { rows?: unknown[] } | unknown[]): Record<string, unknown>[] {
+  return (Array.isArray(res) ? res : (res.rows ?? [])) as Record<string, unknown>[];
+}
+
+/** Unique per-run prefix so real-PG runs never collide and clean up safely. */
+const T = `hier-a-${randomUUID().slice(0, 8)}`;
+
+/** Minimal valid event row; overrides compose the negative cases. */
+type EventInsert = typeof hierarchyAuditEvents.$inferInsert;
+
+function eventRow(overrides: Partial<EventInsert> = {}): EventInsert {
+  return {
+    actorId: `${T}-actor`,
+    verb: 'create',
+    targetKind: 'company',
+    targetId: randomUUID(),
+    targetSnapshot: { id: 'x', slug: 'x', name: 'x', parentChain: [] },
+    correlationId: `${T}-corr`,
+    idempotencyKey: `${T}-${randomUUID()}`,
+    ...overrides,
+  };
+}
+
+function witnessSuite(getHandle: () => AnyDb): void {
+  const db = () => getHandle().db as unknown as ReturnType<typeof createDb>['db'];
+
+  afterAll(async () => {
+    const d = db();
+    await d.execute(sql`DELETE FROM hierarchy_outbox WHERE idempotency_key LIKE ${T + '%'}`);
+    // Caused events first: the causation self-FK is RESTRICT.
+    await d.execute(
+      sql`DELETE FROM hierarchy_audit_events WHERE idempotency_key LIKE ${T + '%'} AND causation_id IS NOT NULL`,
+    );
+    await d.execute(sql`DELETE FROM hierarchy_audit_events WHERE idempotency_key LIKE ${T + '%'}`);
+    await d.execute(sql`DELETE FROM companies WHERE slug LIKE ${T + '%'}`);
+  });
+
+  // ── CHECK constraints ──────────────────────────────────────────────────────
+
+  it('accepts every declared verb and refuses an undeclared one', async () => {
+    for (const verb of [
+      'create',
+      'rename',
+      'delete',
+      'grant_create',
+      'grant_change',
+      'grant_revoke',
+    ]) {
+      await db().insert(hierarchyAuditEvents).values(eventRow({ verb }));
+    }
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ verb: 'update' })),
+      /verb_check|violates check/i,
+      'undeclared verb must be refused',
+    );
+  });
+
+  it('refuses an undeclared target kind', async () => {
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ targetKind: 'workspace' })),
+      /target_kind_check|violates check/i,
+      'workspace is not an audited target kind (workspace mutation is SOT-side)',
+    );
+  });
+
+  it('requires transfer snapshots exactly on transfers', async () => {
+    const parent = { kind: 'company', id: randomUUID(), slug: 'p' };
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(
+        eventRow({
+          verb: 'transfer',
+          targetKind: 'estate',
+          transferFrom: parent,
+          transferTo: { ...parent, id: randomUUID() },
+        }),
+      );
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ verb: 'transfer' })),
+      /transfer_check|violates check/i,
+      'transfer without source/destination snapshots must be refused',
+    );
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ verb: 'transfer', transferFrom: parent })),
+      /transfer_check|violates check/i,
+      'transfer with only the source snapshot must be refused',
+    );
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ verb: 'create', transferFrom: parent, transferTo: parent })),
+      /transfer_check|violates check/i,
+      'non-transfer with transfer snapshots must be refused',
+    );
+  });
+
+  // ── Idempotency and ordering ───────────────────────────────────────────────
+
+  it('refuses a duplicate idempotency key', async () => {
+    const key = `${T}-dup-${randomUUID()}`;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(eventRow({ idempotencyKey: key }));
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ idempotencyKey: key })),
+      /duplicate key|unique/i,
+    );
+  });
+
+  it('assigns strictly increasing seq in insert order for one target', async () => {
+    const targetId = randomUUID();
+    const k1 = `${T}-seq-1-${randomUUID()}`;
+    const k2 = `${T}-seq-2-${randomUUID()}`;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(eventRow({ targetId, idempotencyKey: k1 }));
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(eventRow({ targetId, verb: 'rename', idempotencyKey: k2 }));
+    const res = rows(
+      await db().execute(
+        sql`SELECT idempotency_key, seq FROM hierarchy_audit_events WHERE target_id = ${targetId} ORDER BY seq ASC`,
+      ),
+    );
+    expect(res.map((r) => r['idempotency_key'])).toEqual([k1, k2]);
+    expect(Number(res[1]!['seq'])).toBeGreaterThan(Number(res[0]!['seq']));
+  });
+
+  // ── Deletion-safe linkage (§5.2) ───────────────────────────────────────────
+
+  it('has no foreign key into any class table, and events survive target deletion', async () => {
+    const fks = rows(
+      await db().execute(sql`
+        SELECT ccu.table_name AS referenced_table
+        FROM information_schema.table_constraints tc
+        JOIN information_schema.constraint_column_usage ccu
+          ON ccu.constraint_name = tc.constraint_name AND ccu.constraint_schema = tc.constraint_schema
+        WHERE tc.constraint_type = 'FOREIGN KEY' AND tc.table_name = 'hierarchy_audit_events'
+      `),
+    );
+    // The causation self-FK is the ONLY foreign key on the events table.
+    expect([...new Set(fks.map((r) => r['referenced_table']))]).toEqual(['hierarchy_audit_events']);
+
+    const companyId = randomUUID();
+    await db()
+      .insert(companies)
+      .values({ id: companyId, name: 'Doomed', slug: `${T}-doomed` });
+    const key = `${T}-survive-${randomUUID()}`;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(
+        eventRow({
+          verb: 'delete',
+          targetId: companyId,
+          targetSnapshot: { id: companyId, slug: `${T}-doomed`, name: 'Doomed', parentChain: [] },
+          idempotencyKey: key,
+        }),
+      );
+    await db().execute(sql`DELETE FROM companies WHERE id = ${companyId}`);
+    const after = rows(
+      await db().execute(
+        sql`SELECT target_snapshot FROM hierarchy_audit_events WHERE idempotency_key = ${key}`,
+      ),
+    );
+    expect(after).toHaveLength(1);
+    expect((after[0]!['target_snapshot'] as { id: string }).id).toBe(companyId);
+  });
+
+  it('enforces the causation self-FK and RESTRICTs deleting a cause', async () => {
+    await expectViolation(
+      db()
+        .insert(hierarchyAuditEvents)
+        .values(eventRow({ causationId: randomUUID() })),
+      /foreign key/i,
+      'causation must reference an existing event',
+    );
+    const causeKey = `${T}-cause-${randomUUID()}`;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(eventRow({ verb: 'delete', idempotencyKey: causeKey }));
+    const cause = rows(
+      await db().execute(
+        sql`SELECT id FROM hierarchy_audit_events WHERE idempotency_key = ${causeKey}`,
+      ),
+    )[0]!;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(
+        eventRow({ verb: 'grant_revoke', targetKind: 'grant', causationId: cause['id'] as string }),
+      );
+    await expectViolation(
+      db().execute(sql`DELETE FROM hierarchy_audit_events WHERE id = ${cause['id'] as string}`),
+      /foreign key/i,
+      'a cause with dependent events must not be deletable',
+    );
+  });
+
+  // ── Outbox shape ───────────────────────────────────────────────────────────
+
+  it('outbox rows require an existing event, one outbox row per event, unique idempotency', async () => {
+    await expectViolation(
+      db()
+        .insert(hierarchyOutbox)
+        .values({
+          eventId: randomUUID(),
+          idempotencyKey: `${T}-ob-${randomUUID()}`,
+          correlationId: `${T}-corr`,
+        }),
+      /foreign key/i,
+      'outbox must reference an existing event',
+    );
+    const key = `${T}-ob-${randomUUID()}`;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(eventRow({ idempotencyKey: key }));
+    const event = rows(
+      await db().execute(sql`SELECT id FROM hierarchy_audit_events WHERE idempotency_key = ${key}`),
+    )[0]!;
+    const eventId = event['id'] as string;
+    await db()
+      .insert(hierarchyOutbox)
+      .values({ eventId, idempotencyKey: key, correlationId: `${T}-corr` });
+    await expectViolation(
+      db()
+        .insert(hierarchyOutbox)
+        .values({ eventId, idempotencyKey: `${T}-ob2-${randomUUID()}`, correlationId: `${T}-c` }),
+      /duplicate key|unique/i,
+      'one outbox record per event',
+    );
+    await expectViolation(
+      db().execute(
+        sql`INSERT INTO hierarchy_outbox (event_id, idempotency_key, correlation_id, status)
+            VALUES (${eventId}, ${`${T}-ob3-${randomUUID()}`}, 'c', 'failed')`,
+      ),
+      /invalid input value for enum|22P02/i,
+      'status outside pending/processing/delivered must be refused',
+    );
+  });
+
+  it('outbox FK RESTRICTs event deletion while the outbox row exists', async () => {
+    const key = `${T}-obr-${randomUUID()}`;
+    await db()
+      .insert(hierarchyAuditEvents)
+      .values(eventRow({ idempotencyKey: key }));
+    const event = rows(
+      await db().execute(sql`SELECT id FROM hierarchy_audit_events WHERE idempotency_key = ${key}`),
+    )[0]!;
+    await db()
+      .insert(hierarchyOutbox)
+      .values({
+        eventId: event['id'] as string,
+        idempotencyKey: key,
+        correlationId: `${T}-corr`,
+      });
+    await expectViolation(
+      db().execute(sql`DELETE FROM hierarchy_audit_events WHERE id = ${event['id'] as string}`),
+      /foreign key/i,
+    );
+  });
+}
+
+// ── Leg 1: PGlite (always runs — local witness signal) ───────────────────────
+
+describe('hierarchy audit witnesses — PGlite', () => {
+  let dir: string;
+  let handle: ReturnType<typeof createPgliteDb>;
+
+  beforeAll(async () => {
+    dir = mkdtempSync(join(tmpdir(), 'hier-audit-witness-'));
+    handle = createPgliteDb(dir);
+    await runPgliteMigrations(handle);
+  });
+
+  afterAll(async () => {
+    await handle.close();
+    rmSync(dir, { recursive: true, force: true });
+  });
+
+  witnessSuite(() => handle as unknown as AnyDb);
+});
+
+// ── Leg 2: real PostgreSQL (§6.8 — binding witness, ci-postgres in CI) ───────
+
+const hasPostgres = Boolean(process.env['DATABASE_URL']);
+
+describe.skipIf(!hasPostgres)('hierarchy audit witnesses — real PostgreSQL', () => {
+  let handle: ReturnType<typeof createDb>;
+
+  beforeAll(() => {
+    handle = createDb(process.env['DATABASE_URL']!);
+  });
+
+  afterAll(async () => {
+    await handle.close();
+  });
+
+  witnessSuite(() => handle as unknown as AnyDb);
+});

packages/db/src/hierarchy-schema.witness.test.ts

@@ -44,7 +44,7 @@ type AnyDb = {
 
 /** Column allowlist — the exact declared sets of §2/§3. Nothing else. */
 const COLUMN_ALLOWLIST: Record<string, string[]> = {
-  companies: ['id', 'name', 'slug', 'created_at', 'updated_at'],
+  companies: ['id', 'name', 'slug', 'visibility', 'created_at', 'updated_at'],
   estates: ['id', 'name', 'slug', 'company_id'],
   platform_projects: ['id', 'name', 'slug', 'estate_id'],
   workspaces: ['id', 'name', 'slug', 'platform_project_id'],
@@ -377,7 +377,61 @@ function witnessSuite(getHandle: () => AnyDb): void {
     // Control: same subject and target with a different role is a new grant.
     await db()
       .insert(hierarchyGrants)
-      .values({ userId: userA, companyId, role: `${T}-other-role`, grantedBy: userA });
+      .values({ userId: userA, companyId, role: 'member', grantedBy: userA });
+  });
+
+  // ── §2.6 role vocabulary CHECK ─────────────────────────────────────────────
+
+  it('refuses a grant role outside the ratified vocabulary, accepts each ratified role', async () => {
+    await expectViolation(
+      db()
+        .insert(hierarchyGrants)
+        .values({ userId: userB, companyId, role: 'superuser', grantedBy: userA }),
+      /check constraint/i,
+    );
+    // Serialized namespaced forms are storage-invalid too: rows hold bare roles.
+    await expectViolation(
+      db()
+        .insert(hierarchyGrants)
+        .values({ userId: userB, companyId, role: 'hierarchy:owner', grantedBy: userA }),
+      /check constraint/i,
+    );
+    for (const role of ['viewer', 'member', 'owner'] as const) {
+      await db()
+        .insert(hierarchyGrants)
+        .values({ userId: userB, estateId, role, grantedBy: userA });
+    }
+    await db().execute(
+      sql`DELETE FROM hierarchy_grants WHERE user_id = ${userB} AND estate_id = ${estateId}`,
+    );
+  });
+
+  // ── §2.8 visibility column ─────────────────────────────────────────────────
+
+  it('defaults companies.visibility to private and refuses values outside the class', async () => {
+    const visId = randomUUID();
+    await db().execute(
+      sql`INSERT INTO companies (id, name, slug) VALUES (${visId}, 'Vis', ${T + '-vis'})`,
+    );
+    const res = rows(await db().execute(sql`SELECT visibility FROM companies WHERE id = ${visId}`));
+    expect(res[0]!['visibility']).toBe('private');
+    await db().execute(
+      sql`INSERT INTO companies (id, name, slug, visibility) VALUES (${randomUUID()}, 'Vis D', ${T + '-vis-d'}, 'directory')`,
+    );
+    await expectViolation(
+      db().execute(
+        sql`INSERT INTO companies (id, name, slug, visibility) VALUES (${randomUUID()}, 'Vis X', ${T + '-vis-x'}, 'public')`,
+      ),
+      /check constraint/i,
+    );
+    await expectViolation(
+      db().execute(sql`UPDATE companies SET visibility = 'hidden' WHERE id = ${visId}`),
+      /check constraint/i,
+    );
+    await expectViolation(
+      db().execute(sql`UPDATE companies SET visibility = NULL WHERE id = ${visId}`),
+      /null value|not-null/i,
+    );
   });
 
   // ── §6.1 NOT NULLs ─────────────────────────────────────────────────────────
@@ -391,7 +445,7 @@ function witnessSuite(getHandle: () => AnyDb): void {
     );
     await expectViolation(
       db().execute(
-        sql`INSERT INTO hierarchy_grants (user_id, company_id, role, granted_by) VALUES (${userA}, ${companyId}, 'x', NULL)`,
+        sql`INSERT INTO hierarchy_grants (user_id, company_id, role, granted_by) VALUES (${userA}, ${companyId}, 'viewer', NULL)`,
       ),
       /null value|not-null/i,
     );

packages/db/src/hierarchy-writer-coverage.test.ts

@@ -123,19 +123,21 @@
  *     tracked for M4-1b consideration); the counterfactual — flagging every
  *     bare identifier call — false-positives on essentially all callback
  *     code. Reviews of modules touching db handles carry this residual.
- *   - The scan perimeter is <root>/<pkg>/src for the three roots; production
- *     TS outside a src/ directory (e.g. packages/mosaic/framework/**) is not
- *     scanned (verified free of db/driver/execute references at review time).
- *     Files excluded from the scan — test files and out-of-src modules — are
- *     also invisible as import-graph CONDUITS: test files are emitted to
- *     dist, so a production module could launder a symbol or capability
- *     through a re-export in one. Importing a test module from production
- *     code is anomalous and review-visible; the blind spot is accepted as a
- *     residual, not closed.
+ *   - The scan perimeter is the full <root>/<pkg> tree for the three roots
+ *     (build output, tool caches, and dot-directories excluded), so
+ *     production TS outside src/ — package configs, e2e helpers,
+ *     packages/mosaic/framework/** — is scanned and conduit-visible
+ *     (widened from src/-only in M4-1b-i; the widened set was measured free
+ *     of every trigger token at the time). Files excluded from the scan —
+ *     test files — are still invisible as import-graph CONDUITS: test files
+ *     are emitted to dist, so a production module could launder a symbol or
+ *     capability through a re-export in one. Importing a test module from
+ *     production code is anomalous and review-visible; that blind spot is
+ *     accepted as a residual, not closed.
  *
- * The writer allowlist names hierarchy command/repository modules ONLY. It is
- * empty today: the hierarchy command family (M4-1b) has not landed, so no
- * production module may write the class tables. The infrastructure register
+ * The writer allowlist names hierarchy command/repository modules ONLY. Its
+ * single entry is the M4-1b-ii hierarchy command repository — the sole
+ * production module permitted to write the class tables. The infrastructure register
  * holds legitimate non-hierarchy raw execution; registered modules are exempt
  * from prong (iii) only — prongs (i) and (ii) apply to them with no
  * exemption, and no registered module may appear on the writer allowlist.
@@ -179,12 +181,15 @@ const CLASS_TABLES = [
 
 /**
  * Writer allowlist (§6.3b): hierarchy command/repository modules only.
- * EMPTY until the hierarchy command family lands (M4-1b). Adding a module
- * here is a contract-conformance decision reviewed under §5.1 — the module
- * must be part of the Gateway hierarchy command path, and it must not export
- * a function that executes caller-supplied SQL.
+ * Adding a module here is a contract-conformance decision reviewed under
+ * §5.1 — the module must be part of the Gateway hierarchy command path, and
+ * it must not export a function that executes caller-supplied SQL.
  */
-const WRITER_ALLOWLIST: string[] = [];
+const WRITER_ALLOWLIST: string[] = [
+  // The hierarchy command repository (M4-1b-ii): the sole class-table
+  // writer; every mutation is audited on its own transaction (§5.2).
+  'apps/gateway/src/hierarchy/hierarchy.repository.ts',
+];
 
 /**
  * Infrastructure register: closed enumeration of legitimate non-hierarchy raw
@@ -291,20 +296,23 @@ function isTestPath(rel: string): boolean {
   );
 }
 
+/** Directory names excluded from the walk: build output and tool caches only. */
+const EXCLUDED_DIRS = new Set(['node_modules', 'dist', 'build', 'coverage', 'test-results']);
+
 function collectSources(): string[] {
   const files: string[] = [];
   for (const root of SCAN_ROOTS) {
     const rootDir = join(REPO_ROOT, root);
     if (!existsSync(rootDir)) continue;
     for (const pkg of readdirSync(rootDir)) {
-      const srcDir = join(rootDir, pkg, 'src');
-      if (!existsSync(srcDir) || !statSync(srcDir).isDirectory()) continue;
+      const pkgDir = join(rootDir, pkg);
+      if (!statSync(pkgDir).isDirectory()) continue;
       const walk = (dir: string): void => {
         for (const entry of readdirSync(dir)) {
           const full = join(dir, entry);
           const st = statSync(full);
           if (st.isDirectory()) {
-            if (entry === 'node_modules' || entry === 'dist') continue;
+            if (EXCLUDED_DIRS.has(entry) || entry.startsWith('.')) continue;
             walk(full);
           } else if (EXTENSIONS.has(full.slice(full.lastIndexOf('.')))) {
             const rel = relative(REPO_ROOT, full).split(sep).join('/');
@@ -312,7 +320,7 @@ function collectSources(): string[] {
           }
         }
       };
-      walk(srcDir);
+      walk(pkgDir);
     }
   }
   return files.sort();

packages/db/src/schema.ts

@@ -4,6 +4,7 @@
  */
 
 import { sql } from 'drizzle-orm';
+import type { AnyPgColumn } from 'drizzle-orm/pg-core';
 import {
   pgTable,
   pgEnum,
@@ -1062,13 +1063,24 @@ export const federationEnrollmentTokens = pgTable('federation_enrollment_tokens'
 // command family only (§5.1), enforced by the writer-coverage assertion
 // (§6.3b) — do not add writers outside that allowlist.
 
-export const companies = pgTable('companies', {
-  id: uuid('id').primaryKey().defaultRandom(),
-  name: text('name').notNull(),
-  slug: text('slug').notNull().unique(),
-  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
-  updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
-});
+/** Company visibility classes (contract 1 §2.8, Ruling 4b): 'private' is the
+ * only creatable class (§5.5 — creation carries no visibility argument);
+ * 'directory' discloses existence/name/slug to all users and is entered only
+ * through the admin-gated visibility-change command. */
+export const COMPANY_VISIBILITY = ['private', 'directory'] as const;
+
+export const companies = pgTable(
+  'companies',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    name: text('name').notNull(),
+    slug: text('slug').notNull().unique(),
+    visibility: text('visibility').notNull().default('private'),
+    createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+    updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+  },
+  () => [check('companies_visibility_check', sql`visibility IN ('private', 'directory')`)],
+);
 
 export const estates = pgTable(
   'estates',
@@ -1109,6 +1121,10 @@ export const workspaces = pgTable(
   (t) => [unique('workspaces_platform_project_slug_uniq').on(t.platformProjectId, t.slug)],
 );
 
+/** Grant role vocabulary (contract 2 §2): totally ordered, viewer ⊂ member ⊂
+ * owner. Order in this tuple IS the ordering — index = strength. */
+export const HIERARCHY_GRANT_ROLES = ['viewer', 'member', 'owner'] as const;
+
 export const hierarchyGrants = pgTable(
   'hierarchy_grants',
   {
@@ -1125,7 +1141,8 @@ export const hierarchyGrants = pgTable(
     platformProjectId: uuid('platform_project_id').references(() => platformProjects.id, {
       onDelete: 'cascade',
     }),
-    // Role vocabulary and its CHECK constraint are contract 2 §2 (M4-2).
+    // Role vocabulary per contract 2 §2: exactly viewer ⊂ member ⊂ owner,
+    // totally ordered; CHECK below closes the column to that vocabulary.
     role: text('role').notNull(),
     grantedBy: text('granted_by')
       .notNull()
@@ -1133,6 +1150,7 @@ export const hierarchyGrants = pgTable(
     createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
   },
   (t) => [
+    check('hierarchy_grants_role_check', sql`role IN ('viewer', 'member', 'owner')`),
     check('hierarchy_grants_subject_check', sql`num_nonnulls(user_id, team_id) = 1`),
     check(
       'hierarchy_grants_target_check',
@@ -1152,3 +1170,112 @@ export const hierarchyGrants = pgTable(
     index('hierarchy_grants_granted_by_idx').on(t.grantedBy),
   ],
 );
+
+// ─── Hierarchy audit events + outbox (contract 1 §5.2) ──────────────────────
+// NOT part of the record class (the class is exactly the five tables above).
+// Append-only semantic audit log for hierarchy mutations, with a dedicated
+// transactional outbox — hierarchy events are not workspace-scoped rows and
+// do not ride the workspace outbox. Deletion-safe linkage: events reference
+// their target by an immutable snapshot (id, slug, parent chain at event
+// time), never by a foreign key into the class tables, so append-only events
+// survive the deletion of their target. Append-only is enforced at the
+// application layer (the hierarchy audit repository exposes no update/delete
+// path for events); REQ-AUD-001's INSERT/SELECT-only database role is a
+// deployment concern outside this schema.
+
+export const HIERARCHY_AUDIT_VERBS = [
+  'create',
+  'rename',
+  'transfer',
+  'visibility_change',
+  'delete',
+  'grant_create',
+  'grant_change',
+  'grant_revoke',
+] as const;
+
+export const HIERARCHY_AUDIT_TARGET_KINDS = [
+  'company',
+  'estate',
+  'platform_project',
+  'grant',
+] as const;
+
+export const hierarchyAuditEvents = pgTable(
+  'hierarchy_audit_events',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    // Global append order; per-target ordering (REQ-AUD-001) is a filter on
+    // target_id ordered by seq.
+    seq: bigint('seq', { mode: 'number' }).notNull().generatedAlwaysAsIdentity(),
+    // No FK: audit events outlive every principal and every target (§5.2).
+    actorId: text('actor_id').notNull(),
+    verb: text('verb').notNull(),
+    targetKind: text('target_kind').notNull(),
+    targetId: uuid('target_id').notNull(),
+    // Immutable snapshot at event time. Node events: { id, slug, name,
+    // parentChain: [{ kind, id, slug }, …] root-first }. Grant events:
+    // { id, subject: { userId | teamId }, target: { kind, id }, role }
+    // (subject and role per contract 2 §4.4).
+    targetSnapshot: jsonb('target_snapshot').notNull(),
+    // Present exactly on transfers: snapshot of the source/destination
+    // parent ({ kind, id, slug }), CHECK-enforced below.
+    transferFrom: jsonb('transfer_from'),
+    transferTo: jsonb('transfer_to'),
+    correlationId: text('correlation_id').notNull(),
+    // Prior event in the causal chain (e.g. cascaded grant_revoke events
+    // caused by a node delete). Self-FK RESTRICT keeps the chain intact.
+    causationId: uuid('causation_id').references((): AnyPgColumn => hierarchyAuditEvents.id, {
+      onDelete: 'restrict',
+    }),
+    idempotencyKey: text('idempotency_key').notNull(),
+    occurredAt: timestamp('occurred_at', { withTimezone: true }).notNull().defaultNow(),
+  },
+  (t) => [
+    uniqueIndex('hierarchy_audit_events_idempotency_idx').on(t.idempotencyKey),
+    uniqueIndex('hierarchy_audit_events_seq_idx').on(t.seq),
+    index('hierarchy_audit_events_target_seq_idx').on(t.targetId, t.seq),
+    index('hierarchy_audit_events_correlation_idx').on(t.correlationId),
+    check(
+      'hierarchy_audit_events_verb_check',
+      sql`verb IN ('create', 'rename', 'transfer', 'visibility_change', 'delete', 'grant_create', 'grant_change', 'grant_revoke')`,
+    ),
+    check(
+      'hierarchy_audit_events_target_kind_check',
+      sql`target_kind IN ('company', 'estate', 'platform_project', 'grant')`,
+    ),
+    check(
+      'hierarchy_audit_events_transfer_check',
+      sql`(verb = 'transfer') = (transfer_from IS NOT NULL AND transfer_to IS NOT NULL)`,
+    ),
+  ],
+);
+
+export const hierarchyOutboxStatusEnum = pgEnum('hierarchy_outbox_status', [
+  'pending',
+  'processing',
+  'delivered',
+]);
+
+export const hierarchyOutbox = pgTable(
+  'hierarchy_outbox',
+  {
+    id: uuid('id').primaryKey().defaultRandom(),
+    // FK into the append-only events table (not a class table): never
+    // dangles, so RESTRICT is safe and keeps event/outbox integrity.
+    eventId: uuid('event_id')
+      .notNull()
+      .references(() => hierarchyAuditEvents.id, { onDelete: 'restrict' }),
+    idempotencyKey: text('idempotency_key').notNull(),
+    correlationId: text('correlation_id').notNull(),
+    status: hierarchyOutboxStatusEnum('status').notNull().default('pending'),
+    createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+    updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),
+    deliveredAt: timestamp('delivered_at', { withTimezone: true }),
+  },
+  (t) => [
+    uniqueIndex('hierarchy_outbox_event_idx').on(t.eventId),
+    uniqueIndex('hierarchy_outbox_idempotency_idx').on(t.idempotencyKey),
+    index('hierarchy_outbox_status_created_idx').on(t.status, t.createdAt),
+  ],
+);