compose: add wrapper-first dogfood workspace (#1488)

Co-authored-by: marcie <[email protected]>

.env.example

@@ -6,3 +6,11 @@ VALKEY_HOST_PORT=6380
 GATEWAY_HOST_PORT=14242
 # Registry image override (defaults to a local build of docker/gateway.Dockerfile):
 # GATEWAY_IMAGE=git.mosaicstack.dev/mosaicstack/stack/gateway:sha-acf640d
+
+# Optional explicit dogfood overlay (docker-compose.dogfood.yml).
+# All three paths are required when that overlay is used. Use a dedicated
+# next-based worktree, its canonical clone's .git directory, and the external
+# home of the unprivileged stack-dogfood seat.
+# MOSAIC_DOGFOOD_WORKTREE=/home/example/src/mosaic-stack-worktrees/dogfood-1487
+# MOSAIC_DOGFOOD_COMMON_GIT_DIR=/home/example/src/mosaic-stack/.git
+# MOSAIC_DOGFOOD_SEAT_HOME=/home/example/.mosaic/fleet/agents/stack-dogfood

README.md

@@ -208,6 +208,50 @@ mosaic telemetry upload        # Dry-run unless opted in
 
 Consent state is persisted in config. Remote upload is a no-op until you run `mosaic telemetry opt-in`.
 
+## Standalone container deployment
+
+The `stack` profile runs PostgreSQL, Valkey, the gateway, and the bundled webUI. Copy
+`.env.example` to `.env`, generate `BETTER_AUTH_SECRET`, then start the profile:
+
+```bash
+cp .env.example .env
+printf 'BETTER_AUTH_SECRET=%s\n' "$(openssl rand -hex 32)" >> .env
+docker compose --profile stack up -d
+```
+
+The optional dogfood overlay gives one dedicated in-stack agent a writable stack
+worktree and its own read-only credential slot. It does not mount the fleet brain or
+any other seat. Prepare a `next`-based worktree and an unprivileged `stack-dogfood`
+seat outside the container, then set these paths in `.env`:
+
+```dotenv
+MOSAIC_DOGFOOD_WORKTREE=/path/to/mosaic-stack-worktrees/dogfood-1487
+MOSAIC_DOGFOOD_COMMON_GIT_DIR=/path/to/mosaic-stack/.git
+MOSAIC_DOGFOOD_SEAT_HOME=/path/to/.mosaic/fleet/agents/stack-dogfood
+```
+
+The common Git directory must match the worktree's `.git` pointer. The seat home
+must contain only that seat's credential at
+`secrets/gitea-mosaicstack-stack-dogfood.token`. Never place the token value in
+`.env`. Start the overlay with:
+
+```bash
+docker compose \
+  -f docker-compose.yml \
+  -f docker-compose.dogfood.yml \
+  --profile stack up -d
+```
+
+The overlay removes the general shell tool for every session, including admins.
+File tools stay inside the mounted checkout. Two dedicated delivery tools stage
+explicit paths, run the CI queue guard, push through `git-credential-mosaic`, and
+open PRs through `pr-create.sh`. They resolve only the `stack-dogfood` slot and fail
+if it is absent. The overlay enables Docker's init process so the R4 helper can
+establish the gateway's seat lineage below PID 1.
+
+This deployment route is separate from the local source-development restrictions
+below.
+
 ## Development
 
 ### Prerequisites

apps/gateway/src/agent/agent.service.ts

@@ -27,10 +27,11 @@ import { McpClientService } from '../mcp-client/mcp-client.service.js';
 import { SkillLoaderService } from './skill-loader.service.js';
 import { createBrainTools } from './tools/brain-tools.js';
 import { createCoordTools } from './tools/coord-tools.js';
+import { createDeliveryTools } from './tools/delivery-tools.js';
 import { createMemoryTools } from './tools/memory-tools.js';
 import { createFileTools } from './tools/file-tools.js';
 import { createGitTools } from './tools/git-tools.js';
-import { createShellTools } from './tools/shell-tools.js';
+import { createShellToolsIfEnabled } from './tools/shell-tools.js';
 import { createWebTools } from './tools/web-tools.js';
 import { createSearchTools } from './tools/search-tools.js';
 import type { SessionInfoDto, SessionMetrics } from './session.dto.js';
@@ -167,7 +168,8 @@ export class AgentService implements OnModuleDestroy {
       ),
       ...createFileTools(sandboxDir),
       ...createGitTools(sandboxDir),
-      ...createShellTools(sandboxDir),
+      ...createShellToolsIfEnabled(sandboxDir),
+      ...createDeliveryTools(sandboxDir),
       ...createWebTools(),
       ...createSearchTools(),
     ];

apps/gateway/src/agent/tools/delivery-tools.test.ts

@@ -0,0 +1,210 @@
+import { afterEach, describe, expect, it } from 'vitest';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import type { ToolDefinition } from '@mariozechner/pi-coding-agent';
+import { createFileTools } from './file-tools.js';
+import { createShellTools, createShellToolsIfEnabled } from './shell-tools.js';
+import {
+  createDeliveryTools,
+  type DeliveryToolEnvironment,
+  type ProcessResult,
+  type ProcessRunner,
+} from './delivery-tools.js';
+
+const tempDirs: string[] = [];
+
+function tempDir(prefix: string): string {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), prefix));
+  tempDirs.push(dir);
+  return dir;
+}
+
+function textOf(result: unknown): string {
+  const typed = result as { content: Array<{ text: string }> };
+  return typed.content.map((item) => item.text).join('\n');
+}
+
+async function execute(tool: ToolDefinition, params: Record<string, unknown>): Promise<unknown> {
+  return (
+    tool.execute as unknown as (id: string, input: Record<string, unknown>) => Promise<unknown>
+  )('test-call', params);
+}
+
+function ok(stdout = ''): ProcessResult {
+  return { exitCode: 0, stdout, stderr: '', timedOut: false };
+}
+
+function deliveryEnv(extra: Partial<DeliveryToolEnvironment> = {}): DeliveryToolEnvironment {
+  return {
+    AGENT_DELIVERY_ENABLED: 'true',
+    MOSAIC_GIT_TOOLS_DIR: '/opt/mosaic/tools/git',
+    MOSAIC_GIT_IDENTITY: 'stack-dogfood',
+    MOSAIC_AGENT_NAME: 'stack-dogfood',
+    MOSAIC_BRAIN_HOME: '/opt/mosaic/brain',
+    MOSAIC_INTEGRATION_TRUNK: 'next',
+    HOME: '/home/node',
+    PATH: '/usr/bin:/bin',
+    ...extra,
+  };
+}
+
+afterEach(() => {
+  for (const dir of tempDirs.splice(0)) {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+describe('dogfood execution boundary', () => {
+  it('removes shell_exec mechanically while its first-token bypass red control stays live', async () => {
+    const sandbox = tempDir('mosaic-shell-boundary-');
+    expect(createShellToolsIfEnabled(sandbox, { AGENT_SHELL_ENABLED: 'false' })).toEqual([]);
+
+    const redControl = createShellTools(sandbox)[0]!;
+    const result = await execute(redControl, { command: 'env printf FIRST_TOKEN_BYPASS' });
+    expect(textOf(result)).toContain('FIRST_TOKEN_BYPASS');
+  });
+
+  it('refuses an outside-sandbox token-shaped read and proves the path guard is the enforcement', async () => {
+    const root = tempDir('mosaic-file-boundary-');
+    const sandbox = path.join(root, 'workspace', 'stack');
+    const token = path.join(
+      root,
+      'brain',
+      'fleet',
+      'agents',
+      'stack-dogfood',
+      'secrets',
+      'gitea-mosaicstack-stack-dogfood.token',
+    );
+    fs.mkdirSync(sandbox, { recursive: true });
+    fs.mkdirSync(path.dirname(token), { recursive: true });
+    fs.writeFileSync(token, 'OUTSIDE_SANDBOX_SENTINEL');
+
+    const read = createFileTools(sandbox).find((tool) => tool.name === 'fs_read_file')!;
+    const refused = await execute(read, { path: token });
+    expect(textOf(refused)).toContain('Path escape attempt blocked');
+    expect(textOf(refused)).not.toContain('OUTSIDE_SANDBOX_SENTINEL');
+
+    fs.symlinkSync(token, path.join(sandbox, 'credential.token'));
+    const symlinkRefused = await execute(read, { path: 'credential.token' });
+    expect(textOf(symlinkRefused)).toContain('Path escape attempt blocked');
+    expect(textOf(symlinkRefused)).not.toContain('OUTSIDE_SANDBOX_SENTINEL');
+
+    const redRead = createFileTools(root).find((tool) => tool.name === 'fs_read_file')!;
+    const redControl = await execute(redRead, { path: token });
+    expect(textOf(redControl)).toContain('OUTSIDE_SANDBOX_SENTINEL');
+  });
+});
+
+describe('delivery tools', () => {
+  it('stay absent unless explicitly enabled and reject identity mismatch', () => {
+    const sandbox = tempDir('mosaic-delivery-disabled-');
+    expect(createDeliveryTools(sandbox, {})).toEqual([]);
+    expect(() =>
+      createDeliveryTools(sandbox, deliveryEnv({ MOSAIC_AGENT_NAME: 'another-seat' })),
+    ).toThrow('matching safe MOSAIC agent and git identities');
+  });
+
+  it('publishes through execFile-only git and queue operations with a scrubbed environment', async () => {
+    const sandbox = tempDir('mosaic-delivery-publish-');
+    fs.writeFileSync(path.join(sandbox, 'change.md'), 'change');
+    const calls: Array<{ file: string; args: readonly string[]; env: NodeJS.ProcessEnv }> = [];
+    const runner: ProcessRunner = async (file, args, options) => {
+      calls.push({ file, args, env: options.env });
+      if (args[0] === 'branch') return ok('feat/1487-dogfood-proof\n');
+      return ok();
+    };
+    const hostile = {
+      ...deliveryEnv(),
+      BASH_ENV: '/tmp/injected',
+      'BASH_FUNC_read%%': '() { :; }',
+      GITEA_TOKEN: 'must-not-cross',
+    } as DeliveryToolEnvironment;
+    const publish = createDeliveryTools(sandbox, hostile, runner).find(
+      (tool) => tool.name === 'git_publish_branch',
+    )!;
+
+    const result = await execute(publish, {
+      issue: 1487,
+      paths: ['change.md'],
+      commitMessage: 'docs: dogfood proof (#1487)',
+    });
+    expect(textOf(result)).toBe('Published branch feat/1487-dogfood-proof as stack-dogfood.');
+
+    expect(calls.map((call) => call.file)).toEqual([
+      '/usr/bin/git',
+      '/usr/bin/git',
+      '/usr/bin/git',
+      '/opt/mosaic/tools/git/ci-queue-wait.sh',
+      '/usr/bin/git',
+    ]);
+    expect(calls[3]!.args).toEqual(['--purpose', 'push', '-B', 'feat/1487-dogfood-proof']);
+    expect(calls[4]!.args).toEqual(['push', '--set-upstream', 'origin', 'feat/1487-dogfood-proof']);
+    for (const call of calls) {
+      expect(call.file).not.toMatch(/(?:^|\/)sh$/);
+      expect(call.env).not.toHaveProperty('BASH_ENV');
+      expect(Object.keys(call.env).some((key) => key.startsWith('BASH_FUNC_'))).toBe(false);
+      expect(call.env).not.toHaveProperty('GITEA_TOKEN');
+      expect(call.env.MOSAIC_GIT_IDENTITY).toBe('stack-dogfood');
+    }
+  });
+
+  it('opens PRs only through pr-create.sh against next', async () => {
+    const sandbox = tempDir('mosaic-delivery-pr-');
+    const calls: Array<{ file: string; args: readonly string[] }> = [];
+    const runner: ProcessRunner = async (file, args) => {
+      calls.push({ file, args });
+      if (args[0] === 'branch') return ok('feat/1487-dogfood-proof\n');
+      return ok('https://git.mosaicstack.dev/mosaicstack/stack/pulls/999\n');
+    };
+    const openPr = createDeliveryTools(sandbox, deliveryEnv(), runner).find(
+      (tool) => tool.name === 'git_open_pull_request',
+    )!;
+
+    const result = await execute(openPr, {
+      issue: 1487,
+      title: 'docs: dogfood proof',
+      body: 'Measured from the in-stack agent.',
+    });
+    expect(textOf(result)).toContain('/pulls/999');
+    expect(calls[1]!.file).toBe('/opt/mosaic/tools/git/pr-create.sh');
+    expect(calls[1]!.args).toEqual([
+      '-t',
+      'docs: dogfood proof',
+      '-b',
+      'Measured from the in-stack agent.',
+      '-B',
+      'next',
+      '-H',
+      'feat/1487-dogfood-proof',
+      '-i',
+      '1487',
+    ]);
+  });
+
+  it('blocks publish paths outside the sandbox before staging', async () => {
+    const root = tempDir('mosaic-delivery-path-');
+    const sandbox = path.join(root, 'sandbox');
+    const outside = path.join(root, 'outside.md');
+    fs.mkdirSync(sandbox);
+    fs.writeFileSync(outside, 'OUTSIDE_DELIVERY_SENTINEL');
+    const calls: Array<{ file: string; args: readonly string[] }> = [];
+    const runner: ProcessRunner = async (file, args) => {
+      calls.push({ file, args });
+      return args[0] === 'branch' ? ok('feat/1487-dogfood-proof\n') : ok();
+    };
+    const publish = createDeliveryTools(sandbox, deliveryEnv(), runner).find(
+      (tool) => tool.name === 'git_publish_branch',
+    )!;
+
+    const result = await execute(publish, {
+      issue: 1487,
+      paths: [outside],
+      commitMessage: 'docs: must not publish',
+    });
+    expect(textOf(result)).toContain('Path escape attempt blocked');
+    expect(textOf(result)).not.toContain('OUTSIDE_DELIVERY_SENTINEL');
+    expect(calls).toHaveLength(1);
+  });
+});

apps/gateway/src/agent/tools/delivery-tools.ts

@@ -0,0 +1,282 @@
+import { Type } from '@sinclair/typebox';
+import type { ToolDefinition } from '@mariozechner/pi-coding-agent';
+import { spawn } from 'node:child_process';
+import path from 'node:path';
+import { guardPath, SandboxEscapeError } from './path-guard.js';
+
+const PROCESS_TIMEOUT_MS = 120_000;
+const MAX_OUTPUT_BYTES = 100 * 1024;
+const SAFE_IDENTITY = /^[a-z0-9][a-z0-9-]{0,62}$/;
+const SAFE_BRANCH = /^(?:feat|fix|docs|test)\/[a-z0-9][a-z0-9._/-]*$/i;
+
+export interface ProcessResult {
+  exitCode: number | null;
+  stdout: string;
+  stderr: string;
+  timedOut: boolean;
+}
+
+export type ProcessRunner = (
+  file: string,
+  args: readonly string[],
+  options: { cwd: string; env: NodeJS.ProcessEnv; timeoutMs: number },
+) => Promise<ProcessResult>;
+
+export interface DeliveryToolEnvironment {
+  AGENT_DELIVERY_ENABLED?: string;
+  MOSAIC_GIT_TOOLS_DIR?: string;
+  MOSAIC_GIT_IDENTITY?: string;
+  MOSAIC_AGENT_NAME?: string;
+  MOSAIC_BRAIN_HOME?: string;
+  MOSAIC_CREDENTIAL_SPOOL?: string;
+  MOSAIC_CREDENTIAL_LINEAGE_FENCE?: string;
+  MOSAIC_INTEGRATION_TRUNK?: string;
+  HOME?: string;
+  PATH?: string;
+  LANG?: string;
+  LC_ALL?: string;
+}
+
+function runProcess(
+  file: string,
+  args: readonly string[],
+  options: { cwd: string; env: NodeJS.ProcessEnv; timeoutMs: number },
+): Promise<ProcessResult> {
+  return new Promise((resolve) => {
+    const child = spawn(file, [...args], {
+      cwd: options.cwd,
+      env: options.env,
+      shell: false,
+      stdio: ['ignore', 'pipe', 'pipe'],
+    });
+    let stdout = '';
+    let stderr = '';
+    let timedOut = false;
+    let outputBytes = 0;
+
+    const append = (current: string, chunk: Buffer): string => {
+      const remaining = MAX_OUTPUT_BYTES - outputBytes;
+      if (remaining <= 0) return current;
+      outputBytes += chunk.length;
+      return current + chunk.subarray(0, remaining).toString();
+    };
+    child.stdout.on('data', (chunk: Buffer) => {
+      stdout = append(stdout, chunk);
+    });
+    child.stderr.on('data', (chunk: Buffer) => {
+      stderr = append(stderr, chunk);
+    });
+
+    const timer = setTimeout(() => {
+      timedOut = true;
+      child.kill('SIGTERM');
+    }, options.timeoutMs);
+
+    child.on('error', (error) => {
+      clearTimeout(timer);
+      resolve({ exitCode: null, stdout, stderr: `${stderr}${String(error)}`, timedOut });
+    });
+    child.on('close', (exitCode) => {
+      clearTimeout(timer);
+      resolve({ exitCode, stdout, stderr, timedOut });
+    });
+  });
+}
+
+function cleanEnvironment(env: DeliveryToolEnvironment): NodeJS.ProcessEnv {
+  const clean: NodeJS.ProcessEnv = {
+    GIT_TERMINAL_PROMPT: '0',
+  };
+  for (const key of [
+    'HOME',
+    'PATH',
+    'LANG',
+    'LC_ALL',
+    'MOSAIC_GIT_IDENTITY',
+    'MOSAIC_AGENT_NAME',
+    'MOSAIC_BRAIN_HOME',
+    'MOSAIC_CREDENTIAL_SPOOL',
+    'MOSAIC_CREDENTIAL_LINEAGE_FENCE',
+  ] as const) {
+    const value = env[key];
+    if (value !== undefined) clean[key] = value;
+  }
+  return clean;
+}
+
+function textResult(text: string): {
+  content: Array<{ type: 'text'; text: string }>;
+  details: undefined;
+} {
+  return { content: [{ type: 'text', text }], details: undefined };
+}
+
+function describeFailure(label: string, result: ProcessResult): string {
+  if (result.timedOut) return `${label} timed out`;
+  const diagnostic = result.stderr.trim() || result.stdout.trim() || 'no diagnostic output';
+  return `${label} failed (exit ${result.exitCode ?? 'null'}): ${diagnostic}`;
+}
+
+function currentBranchPattern(issue: number): RegExp {
+  return new RegExp(`^(?:feat|fix|docs|test)/${issue}(?:[-/].+)$`, 'i');
+}
+
+export function createDeliveryTools(
+  sandboxDir: string,
+  sourceEnv: DeliveryToolEnvironment = process.env,
+  runner: ProcessRunner = runProcess,
+): ToolDefinition[] {
+  if (sourceEnv.AGENT_DELIVERY_ENABLED !== 'true') return [];
+
+  const identity = sourceEnv.MOSAIC_GIT_IDENTITY ?? '';
+  const agentName = sourceEnv.MOSAIC_AGENT_NAME ?? '';
+  const toolsDir = sourceEnv.MOSAIC_GIT_TOOLS_DIR ?? '';
+  const baseBranch = sourceEnv.MOSAIC_INTEGRATION_TRUNK ?? 'next';
+  if (!SAFE_IDENTITY.test(identity) || identity !== agentName) {
+    throw new Error('Delivery tools require matching safe MOSAIC agent and git identities');
+  }
+  if (!path.isAbsolute(toolsDir)) {
+    throw new Error('Delivery tools require an absolute MOSAIC_GIT_TOOLS_DIR');
+  }
+  if (!SAFE_BRANCH.test(`feat/${baseBranch}`) || baseBranch.includes('/')) {
+    throw new Error('Delivery tools require a safe integration branch name');
+  }
+
+  const env = cleanEnvironment(sourceEnv);
+  const queueGuard = path.join(toolsDir, 'ci-queue-wait.sh');
+  const prCreate = path.join(toolsDir, 'pr-create.sh');
+
+  const run = (file: string, args: readonly string[], timeoutMs = PROCESS_TIMEOUT_MS) =>
+    runner(file, args, { cwd: sandboxDir, env, timeoutMs });
+
+  const readBranch = async (): Promise<{ branch?: string; error?: string }> => {
+    const result = await run('/usr/bin/git', ['branch', '--show-current'], 15_000);
+    if (result.exitCode !== 0) return { error: describeFailure('git branch', result) };
+    const branch = result.stdout.trim();
+    if (!SAFE_BRANCH.test(branch))
+      return { error: `Unsafe delivery branch: ${branch || '<empty>'}` };
+    if (branch === baseBranch || branch === 'main') {
+      return { error: `Refusing delivery from protected branch ${branch}` };
+    }
+    return { branch };
+  };
+
+  const publish: ToolDefinition = {
+    name: 'git_publish_branch',
+    label: 'Publish Git Branch',
+    description:
+      'Stage explicit files in the current sandbox branch, commit them as the dedicated dogfood identity, run the CI queue guard, and push the branch. No shell or raw provider API is used.',
+    parameters: Type.Object({
+      issue: Type.Integer({ minimum: 1, description: 'Tracking issue number' }),
+      paths: Type.Array(Type.String(), {
+        minItems: 1,
+        maxItems: 100,
+        description: 'Files to stage, relative to the sandbox root',
+      }),
+      commitMessage: Type.String({ minLength: 1, maxLength: 4000 }),
+    }),
+    async execute(_toolCallId, params) {
+      const { issue, paths, commitMessage } = params as {
+        issue: number;
+        paths: string[];
+        commitMessage: string;
+      };
+      const branchResult = await readBranch();
+      if (!branchResult.branch) return textResult(`Error: ${branchResult.error}`);
+      const branch = branchResult.branch;
+      if (!currentBranchPattern(issue).test(branch)) {
+        return textResult(`Error: branch ${branch} does not carry issue ${issue}`);
+      }
+
+      const relativePaths: string[] = [];
+      try {
+        const sandboxRoot = guardPath('.', sandboxDir);
+        for (const candidate of paths) {
+          const resolved = guardPath(candidate, sandboxDir);
+          const relative = path.relative(sandboxRoot, resolved);
+          if (!relative || relative.startsWith('..') || path.isAbsolute(relative)) {
+            throw new SandboxEscapeError(candidate, sandboxDir, resolved);
+          }
+          relativePaths.push(relative);
+        }
+      } catch (error) {
+        return textResult(`Error: ${error instanceof Error ? error.message : String(error)}`);
+      }
+
+      const add = await run('/usr/bin/git', ['add', '--', ...relativePaths], 30_000);
+      if (add.exitCode !== 0) return textResult(`Error: ${describeFailure('git add', add)}`);
+
+      const commit = await run(
+        '/usr/bin/git',
+        [
+          '-c',
+          `user.name=${identity}`,
+          '-c',
+          `user.email=${identity}@mosaic.invalid`,
+          'commit',
+          '-m',
+          commitMessage,
+          '--',
+          ...relativePaths,
+        ],
+        60_000,
+      );
+      if (commit.exitCode !== 0)
+        return textResult(`Error: ${describeFailure('git commit', commit)}`);
+
+      const queue = await run(queueGuard, ['--purpose', 'push', '-B', branch]);
+      if (queue.exitCode !== 0) {
+        return textResult(`Error: ${describeFailure('CI queue guard', queue)}`);
+      }
+
+      const push = await run(
+        '/usr/bin/git',
+        ['push', '--set-upstream', 'origin', branch],
+        PROCESS_TIMEOUT_MS,
+      );
+      if (push.exitCode !== 0) return textResult(`Error: ${describeFailure('git push', push)}`);
+
+      return textResult(`Published branch ${branch} as ${identity}.`);
+    },
+  };
+
+  const openPr: ToolDefinition = {
+    name: 'git_open_pull_request',
+    label: 'Open Pull Request',
+    description:
+      'Open a pull request from the current sandbox branch through the Mosaic pr-create wrapper. The wrapper targets the configured integration branch and links the tracking issue.',
+    parameters: Type.Object({
+      issue: Type.Integer({ minimum: 1, description: 'Tracking issue number' }),
+      title: Type.String({ minLength: 1, maxLength: 240 }),
+      body: Type.String({ maxLength: 20_000 }),
+    }),
+    async execute(_toolCallId, params) {
+      const { issue, title, body } = params as { issue: number; title: string; body: string };
+      const branchResult = await readBranch();
+      if (!branchResult.branch) return textResult(`Error: ${branchResult.error}`);
+      const branch = branchResult.branch;
+      if (!currentBranchPattern(issue).test(branch)) {
+        return textResult(`Error: branch ${branch} does not carry issue ${issue}`);
+      }
+
+      const result = await run(prCreate, [
+        '-t',
+        title,
+        '-b',
+        body,
+        '-B',
+        baseBranch,
+        '-H',
+        branch,
+        '-i',
+        String(issue),
+      ]);
+      if (result.exitCode !== 0) {
+        return textResult(`Error: ${describeFailure('pr-create wrapper', result)}`);
+      }
+      return textResult(result.stdout.trim() || `Pull request opened from ${branch}.`);
+    },
+  };
+
+  return [publish, openPr];
+}

apps/gateway/src/agent/tools/file-tools.ts

@@ -1,7 +1,7 @@
 import { Type } from '@sinclair/typebox';
 import type { ToolDefinition } from '@mariozechner/pi-coding-agent';
 import { readFile, writeFile, readdir, stat } from 'node:fs/promises';
-import { guardPath, guardPathUnsafe, SandboxEscapeError } from './path-guard.js';
+import { guardPath, guardWritePath, SandboxEscapeError } from './path-guard.js';
 
 const MAX_READ_BYTES = 512 * 1024; // 512 KB read limit
 const MAX_WRITE_BYTES = 1024 * 1024; // 1 MB write limit
@@ -92,7 +92,7 @@ export function createFileTools(baseDir: string): ToolDefinition[] {
       };
       let safePath: string;
       try {
-        safePath = guardPathUnsafe(path, baseDir);
+        safePath = guardWritePath(path, baseDir);
       } catch (err) {
         if (err instanceof SandboxEscapeError) {
           return {

apps/gateway/src/agent/tools/index.ts

@@ -1,8 +1,9 @@
 export { createBrainTools } from './brain-tools.js';
 export { createCoordTools } from './coord-tools.js';
+export { createDeliveryTools } from './delivery-tools.js';
 export { createFileTools } from './file-tools.js';
 export { createGitTools } from './git-tools.js';
 export { createSearchTools } from './search-tools.js';
-export { createShellTools } from './shell-tools.js';
+export { createShellTools, createShellToolsIfEnabled } from './shell-tools.js';
 export { createWebTools } from './web-tools.js';
 export { createSkillTools } from './skill-tools.js';

apps/gateway/src/agent/tools/path-guard.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { guardPath, guardPathUnsafe, SandboxEscapeError } from './path-guard.js';
+import { guardPath, guardPathUnsafe, guardWritePath, SandboxEscapeError } from './path-guard.js';
 import path from 'node:path';
 import os from 'node:os';
 import fs from 'node:fs';
@@ -101,4 +101,55 @@ describe('guardPath', () => {
       fs.rmSync(tmpDir, { recursive: true, force: true });
     }
   });
+
+  it('rejects a symlink inside the sandbox that resolves outside it', () => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'path-guard-test-'));
+    const outside = fs.mkdtempSync(path.join(os.tmpdir(), 'path-guard-outside-'));
+    try {
+      const target = path.join(outside, 'credential.token');
+      fs.writeFileSync(target, 'OUTSIDE_SYMLINK_SENTINEL');
+      fs.symlinkSync(target, path.join(tmpDir, 'credential.token'));
+      expect(() => guardPath('credential.token', tmpDir)).toThrow(SandboxEscapeError);
+    } finally {
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+      fs.rmSync(outside, { recursive: true, force: true });
+    }
+  });
+});
+
+describe('guardWritePath', () => {
+  it('allows a new file under an existing real sandbox directory', () => {
+    const sandbox = fs.mkdtempSync(path.join(os.tmpdir(), 'path-write-test-'));
+    try {
+      expect(guardWritePath('new.txt', sandbox)).toBe(path.join(sandbox, 'new.txt'));
+    } finally {
+      fs.rmSync(sandbox, { recursive: true, force: true });
+    }
+  });
+
+  it('rejects writes through a file symlink that resolves outside the sandbox', () => {
+    const sandbox = fs.mkdtempSync(path.join(os.tmpdir(), 'path-write-test-'));
+    const outside = fs.mkdtempSync(path.join(os.tmpdir(), 'path-write-outside-'));
+    try {
+      const target = path.join(outside, 'credential.token');
+      fs.writeFileSync(target, 'OUTSIDE_WRITE_SENTINEL');
+      fs.symlinkSync(target, path.join(sandbox, 'credential.token'));
+      expect(() => guardWritePath('credential.token', sandbox)).toThrow(SandboxEscapeError);
+    } finally {
+      fs.rmSync(sandbox, { recursive: true, force: true });
+      fs.rmSync(outside, { recursive: true, force: true });
+    }
+  });
+
+  it('rejects new files under a directory symlink that leaves the sandbox', () => {
+    const sandbox = fs.mkdtempSync(path.join(os.tmpdir(), 'path-write-test-'));
+    const outside = fs.mkdtempSync(path.join(os.tmpdir(), 'path-write-outside-'));
+    try {
+      fs.symlinkSync(outside, path.join(sandbox, 'outside'));
+      expect(() => guardWritePath('outside/new.txt', sandbox)).toThrow(SandboxEscapeError);
+    } finally {
+      fs.rmSync(sandbox, { recursive: true, force: true });
+      fs.rmSync(outside, { recursive: true, force: true });
+    }
+  });
 });

apps/gateway/src/agent/tools/path-guard.ts

@@ -1,47 +1,63 @@
 import path from 'node:path';
 import fs from 'node:fs';
 
-/**
+function isContained(candidate: string, root: string): boolean {
- * Resolves a user-provided path and verifies it is inside the allowed sandbox directory.
+  return candidate === root || candidate.startsWith(root + path.sep);
- * Throws SandboxEscapeError if the resolved path is outside the sandbox.
+}
- *
- * Uses realpathSync to resolve symlinks in the sandbox root. The user-supplied path
- * is checked for containment AFTER lexical resolution but BEFORE resolving any symlinks
- * within the user path — so symlink escape attempts are caught too.
- *
- * @param userPath - The path provided by the agent (may be relative or absolute)
- * @param sandboxDir - The allowed root directory (already validated on session creation)
- * @returns The resolved absolute path, guaranteed to be within sandboxDir
- */
-export function guardPath(userPath: string, sandboxDir: string): string {
-  const resolved = path.resolve(sandboxDir, userPath);
-  const sandboxResolved = fs.realpathSync.native(sandboxDir);
 
-  // Normalize both paths to resolve any symlinks in the sandbox root itself.
+function assertLexicalContainment(userPath: string, sandboxDir: string): string {
-  // For the user path, we check containment BEFORE resolving symlinks in the path
+  const resolved = path.resolve(sandboxDir, userPath);
-  // (so we catch symlink escape attempts too — the resolved path must still be under sandbox)
+  const sandboxAbsolute = path.resolve(sandboxDir);
-  if (!resolved.startsWith(sandboxResolved + path.sep) && resolved !== sandboxResolved) {
+  if (!isContained(resolved, sandboxAbsolute)) {
     throw new SandboxEscapeError(userPath, sandboxDir, resolved);
   }
-
   return resolved;
 }
 
 /**
- * Validates a path without resolving symlinks in the user-provided portion.
+ * Resolve an existing path and verify both its lexical path and real symlink
- * Use for paths that may not exist yet (creates, writes).
+ * target remain inside the sandbox.
- *
+ */
- * Performs a lexical containment check only using path.resolve.
+export function guardPath(userPath: string, sandboxDir: string): string {
+  const resolved = assertLexicalContainment(userPath, sandboxDir);
+  const sandboxReal = fs.realpathSync.native(sandboxDir);
+  const resolvedReal = fs.realpathSync.native(resolved);
+  if (!isContained(resolvedReal, sandboxReal)) {
+    throw new SandboxEscapeError(userPath, sandboxDir, resolvedReal);
+  }
+  return resolvedReal;
+}
+
+/**
+ * Resolve a writable file path whose parent already exists. Existing targets
+ * are resolved fully. New targets use the real parent directory, which blocks
+ * writes through a parent symlink that leaves the sandbox.
+ */
+export function guardWritePath(userPath: string, sandboxDir: string): string {
+  const resolved = assertLexicalContainment(userPath, sandboxDir);
+  const sandboxReal = fs.realpathSync.native(sandboxDir);
+  let writableReal: string;
+  try {
+    writableReal = fs.realpathSync.native(resolved);
+  } catch (error) {
+    const code = (error as NodeJS.ErrnoException).code;
+    if (code !== 'ENOENT') throw error;
+    const parentReal = fs.realpathSync.native(path.dirname(resolved));
+    writableReal = path.join(parentReal, path.basename(resolved));
+  }
+  if (!isContained(writableReal, sandboxReal)) {
+    throw new SandboxEscapeError(userPath, sandboxDir, writableReal);
+  }
+  return writableReal;
+}
+
+/**
+ * Lexical-only validation for non-filesystem pathspecs such as `git diff --`
+ * targets, where the path may name a deleted file and Git does not dereference
+ * a tracked symlink.
  */
 export function guardPathUnsafe(userPath: string, sandboxDir: string): string {
-  const resolved = path.resolve(sandboxDir, userPath);
+  return assertLexicalContainment(userPath, sandboxDir);
-  const sandboxAbs = path.resolve(sandboxDir);
-
-  if (!resolved.startsWith(sandboxAbs + path.sep) && resolved !== sandboxAbs) {
-    throw new SandboxEscapeError(userPath, sandboxDir, resolved);
-  }
-
-  return resolved;
 }
 
 export class SandboxEscapeError extends Error {

apps/gateway/src/agent/tools/shell-tools.ts

@@ -128,6 +128,14 @@ function runCommand(
   });
 }
 
+export function createShellToolsIfEnabled(
+  sandboxDir: string | undefined,
+  env: NodeJS.ProcessEnv = process.env,
+): ToolDefinition[] {
+  if (env['AGENT_SHELL_ENABLED'] === 'false') return [];
+  return createShellTools(sandboxDir);
+}
+
 export function createShellTools(sandboxDir?: string): ToolDefinition[] {
   const defaultCwd = sandboxDir ?? process.cwd();
 

docker-compose.dogfood.yml

@@ -0,0 +1,37 @@
+# Explicit, single-seat dogfood mode for stack-containerization B2.
+# Use with docker-compose.yml. The base stack remains credential-free.
+services:
+  gateway:
+    # The R4 credential helper establishes ownership from process ancestry and
+    # intentionally does not trust PID 1. Keep gateway Node below Docker's init.
+    init: true
+    environment:
+      # Identity and credential layout match a fleet seat. This fixed name prevents
+      # an operator from mounting one seat while attributing actions to another.
+      MOSAIC_AGENT_NAME: stack-dogfood
+      MOSAIC_GIT_IDENTITY: stack-dogfood
+      MOSAIC_BRAIN_HOME: /opt/mosaic/brain
+      AGENT_FILE_SANDBOX_DIR: /workspace/stack
+      # Disable the general shell before admin/user allowlist resolution. Delivery
+      # uses execFile-only tools bound to the queue and PR wrappers below.
+      AGENT_SHELL_ENABLED: 'false'
+      AGENT_DELIVERY_ENABLED: 'true'
+      MOSAIC_GIT_TOOLS_DIR: /opt/mosaic/tools/git
+      MOSAIC_INTEGRATION_TRUNK: next
+      AGENT_USER_TOOLS: fs_read_file,fs_write_file,fs_list_directory,fs_edit_file,git_status,git_log,git_diff,git_publish_branch,git_open_pull_request
+    volumes:
+      # Mount a dedicated worktree, never the canonical clone or divergent local main.
+      - type: bind
+        source: ${MOSAIC_DOGFOOD_WORKTREE:?set to a dedicated next-based stack worktree}
+        target: /workspace/stack
+      # A Git worktree's .git file points into the canonical clone's common Git
+      # directory. Mount that directory at its original absolute path so Git can
+      # resolve the pointer. File tools cannot traverse outside /workspace/stack.
+      - type: bind
+        source: ${MOSAIC_DOGFOOD_COMMON_GIT_DIR:?set to the canonical stack clone .git directory}
+        target: ${MOSAIC_DOGFOOD_COMMON_GIT_DIR:?set to the canonical stack clone .git directory}
+      # Only this seat home enters the container. Other fleet credentials stay outside.
+      - type: bind
+        source: ${MOSAIC_DOGFOOD_SEAT_HOME:?set to the external stack-dogfood seat directory}
+        target: /opt/mosaic/brain/fleet/agents/stack-dogfood
+        read_only: true

docker/gateway.Dockerfile

@@ -29,11 +29,29 @@ ENV NODE_ENV=production
 # $MOSAIC_ROOT/.workspaces (apps/gateway/src/workspace/workspace.service.ts);
 # mount a volume over /opt/mosaic to persist workspaces across container restarts.
 # Intentionally unpinned: Alpine's signed repository is the trust anchor; pinning
-# git was declined so routine base-image security updates remain maintainable.
+# packages was declined so routine base-image security updates remain maintainable.
-RUN apk add --no-cache git \
+# bash/curl/python3 are runtime dependencies of the provider-neutral Mosaic git
+# wrappers. jq supports wrapper discovery for non-canonical Gitea hosts.
+RUN apk add --no-cache bash curl git jq python3 \
   && mkdir -p /opt/mosaic/.workspaces \
   && chown -R node:node /opt/mosaic /app
 ENV MOSAIC_ROOT=/opt/mosaic
+# Dogfood agents use the same fail-closed credential helper, queue guard, and
+# PR-create wrapper as fleet seats. Copy only those operations and their shared
+# dependencies. Merge and infrastructure tools stay out of the image.
+COPY --from=builder /app/packages/mosaic/framework/tools/git/pr-create.sh /opt/mosaic/tools/git/pr-create.sh
+COPY --from=builder /app/packages/mosaic/framework/tools/git/ci-queue-wait.sh /opt/mosaic/tools/git/ci-queue-wait.sh
+COPY --from=builder /app/packages/mosaic/framework/tools/git/detect-platform.sh /opt/mosaic/tools/git/detect-platform.sh
+COPY --from=builder /app/packages/mosaic/framework/tools/git/repo-decl.sh /opt/mosaic/tools/git/repo-decl.sh
+COPY --from=builder /app/packages/mosaic/framework/tools/git/git-credential-mosaic /opt/mosaic/tools/git/git-credential-mosaic
+# R4 hardening (P0-SEC, brain 15f6979a): the credential helper is a pair.
+# python entrypoint (allowlist envp, execve boundary) + the bash implementation
+# it execs. The entrypoint derives the .impl path from its own directory, so the
+# pair sits side by side; system gitconfig keeps pointing at the entrypoint.
+COPY --from=builder /app/packages/mosaic/framework/tools/git/git-credential-mosaic.impl /opt/mosaic/tools/git/git-credential-mosaic.impl
+COPY --from=builder /app/packages/mosaic/framework/tools/_lib/credentials.sh /opt/mosaic/tools/_lib/credentials.sh
+COPY --from=builder /app/packages/mosaic/framework/tools/structure/validate-repo-json.sh /opt/mosaic/tools/structure/validate-repo-json.sh
+RUN git config --system credential.helper /opt/mosaic/tools/git/git-credential-mosaic
 # Use the pnpm deploy output — resolves all deps into a flat, self-contained node_modules
 COPY --chown=node:node --from=builder /deploy/node_modules ./node_modules
 COPY --chown=node:node --from=builder /deploy/package.json ./package.json

packages/mosaic/framework/tools/git/git-credential-mosaic

@@ -1,220 +1,64 @@
-#!/bin/bash
+#!/usr/bin/python3
-# git-credential-mosaic — git credential helper. Resolves a Gitea token from the
+# git-credential-mosaic — production entrypoint (P0-SEC R4, rev-code-02 B1).
-# Mosaic credential store at runtime so remote URLs never embed secrets.
 #
-# Install (one-time, per clone or globally):
+# WHY THIS IS NOT BASH: three review rounds falsified every in-bash startup
-#   git config credential.helper "$HOME/.config/mosaic/tools/git/git-credential-mosaic"
+# guard. A non-interactive bash sources $BASH_ENV and imports exported
+# functions BEFORE the first script line, so read(), unset(), exit(),
+# declare(), printf() — every callable — can be shadows that fake the
+# ancestry, defeat the scrub, or forge diagnostics (rev-code-02 probes 1 and
+# 2, artifacts fc49e9d9 lineage). No in-language dispatch survives that.
 #
-# Per-agent identity (Gate-16 author != reviewer separation):
+# This entrypoint is unshapable at the bash level: python does not read
-#   git config mosaic.gitIdentity <agent-id>   # per-worktree, persists on disk
+# BASH_ENV and imports no bash functions, and the interpreter is pinned by
-#   # or: export MOSAIC_GIT_IDENTITY=<agent-id>
+# absolute shebang (no PATH resolution). It builds the child environment BY
+# ALLOWLIST and execve's the bash implementation directly — the child bash
+# starts with no BASH_ENV, no BASH_FUNC_*, no SHELLOPTS/BASHOPTS, and exactly
+# the variables the credential protocol needs. stdin/stdout/stderr and argv
+# pass through untouched.
 #
-# ── WHY THIS FAILS CLOSED ──────────────────────────────────────────────────────
+# The implementation file (git-credential-mosaic.impl) refuses to run without
-# This helper used to end by emitting the shared account's token for any request
+# the clean-mode marker, so it cannot be invoked directly as a shaped-entry
-# it could not resolve to an identity. A seat with no identity, or with an
+# bypass of this wrapper.
-# identity whose token was never provisioned, therefore received the most
-# privileged credential configured on the host — silently, and indistinguishably
-# from correct operation. Every record it then created (commit, push, PR, review)
-# was attributed to that shared account, so author != reviewer separation was
-# unenforceable and the true actor was unrecoverable after the fact.
-#
-# Under-provisioning must fail loudly, not impersonate. A refused git operation
-# is recoverable in one command; a merged pull request attributed to the wrong
-# principal is not.
-#
-# ── CONTRACT ───────────────────────────────────────────────────────────────────
-#   identity : MOSAIC_GIT_IDENTITY  >  git config mosaic.gitIdentity  >  the
-#              username git supplies on stdin
-#   store    : chosen by what the identity IS, with no precedence and no
-#              cross-store fallback (see "Credential store selection" below)
-#   hit      : emit username + password, exit 0
-#   miss     : emit NOTHING, spool a durable escalation record, explain on
-#              stderr, exit 1 — git surfaces the failure and nothing is attributed
-#   unknown host : exit 0 with no output, no record (passthrough for non-Mosaic
-#              remotes handled by another helper)
-#
-# Backward compatibility is preserved for exactly one case: a host with no fleet
-# and no identity requested still gets the shared account, because on such a host
-# the shared account is the operator's own and there is no attribution to lose.
-# A host that HAS a fleet has agents whose records must be distinguishable, so
-# the shared fallback is refused there.
-#
-# A token is never written to stderr, to the escalation record, or to any log.
 
-[ "$1" = "get" ] || exit 0
+import os
+import sys
 
-host=""; username_in=""
+IMPL = os.path.join(os.path.dirname(os.path.realpath(__file__)), "git-credential-mosaic.impl")
-while IFS= read -r line; do
+# Absolute-path candidates ONLY — never PATH resolution (an attacker-shaped
-  [ -z "$line" ] && break
+# PATH must not choose the interpreter). /usr/bin/bash is the fleet-host
-  case "$line" in
+# layout; /bin/bash is alpine and other FHS variants (found by the T125
-    host=*)     host=${line#host=};;
+# gateway-image verification: the hardcoded /usr/bin/bash made every call
-    username=*) username_in=${line#username=};;
+# exit 127 inside node:22-alpine).
-  esac
+BASH_CANDIDATES = ("/usr/bin/bash", "/bin/bash")
-done
+BASH = next((p for p in BASH_CANDIDATES if os.access(p, os.X_OK)), None)
 
-# Recognized Gitea hosts carry the per-identity token scheme. Anything else is
+# Allowlist: everything else in the environment dies at this boundary. Adding
-# declined quietly — another helper owns it, and refusing would break it.
+# a variable here is a security decision — it crosses into a shell that no
-case "$host" in
+# longer has any startup shaping, but it also becomes the only context the
-  git.uscllc.com)      idpfx=gitea-usc;;
+# implementation can see.
-  git.mosaicstack.dev) idpfx=gitea-mosaicstack;;
+KEEP = (
-  *) exit 0;;
+    "HOME",
-esac
+    "PATH",
+    "LANG",
+    "MOSAIC_GIT_IDENTITY",
+    "MOSAIC_AGENT_NAME",
+    "MOSAIC_BRAIN_HOME",
+    "MOSAIC_CREDENTIAL_SPOOL",
+    "MOSAIC_CREDENTIAL_LINEAGE_FENCE",
+)
 
-ident="$MOSAIC_GIT_IDENTITY"; ident_src="MOSAIC_GIT_IDENTITY"
+env = {"_MOSAIC_HELPER_CLEAN": "1"}
-if [ -z "$ident" ]; then
+for name in KEEP:
-  ident=$(git config --get mosaic.gitIdentity 2>/dev/null)
+    value = os.environ.get(name)
-  ident_src="git config mosaic.gitIdentity"
+    if value is not None:
-fi
+        env[name] = value
-if [ -z "$ident" ]; then
-  ident="$username_in"
-  ident_src="the username git supplied"
-fi
 
-# ── Credential store selection ────────────────────────────────────────────────
+argv = [BASH, IMPL] + sys.argv[1:]
-# An identity is a SEAT or it is a SERVICE, and which one it is determines where
+if BASH is None:
-# its credential lives. There is no precedence rule between the two stores and no
+    sys.stderr.write("git-credential-mosaic: no executable bash at " + " or ".join(BASH_CANDIDATES) + "\n")
-# fallback from one to the other: a seat whose slot is empty fails closed rather
+    sys.exit(127)
-# than reading a service credential that happens to share its name.
+try:
-#
+    os.execve(BASH, argv, env)
-#   seat     — <brain>/fleet/agents/<ident>/ exists
+except OSError as exc:
-#              credential at <brain>/fleet/agents/<ident>/secrets/<idpfx>-<ident>.token
+    sys.stderr.write(f"git-credential-mosaic: entrypoint exec failed: {exc}\n")
-#   service  — it does not
+    sys.exit(127)
-#              credential at ~/.config/mosaic/secrets/gitea-tokens/<idpfx>-<ident>.token
-#
-# One credential, one location. Two copies of one credential diverge, and the
-# stale copy fails in a way that reads as a revoked token rather than as drift.
-#
-# Brain-home resolution mirrors packages/mosaic/src/fleet/brain-home.ts and
-# tools/fleet/start-agent-session.sh: MOSAIC_BRAIN_HOME wins, else ~/.mosaic.
-brain_home="${MOSAIC_BRAIN_HOME:-$HOME/.mosaic}"
-svc_store="$HOME/.config/mosaic/secrets/gitea-tokens"
-
-idtok=""; ident_kind=""
-if [ -n "$ident" ]; then
-  if [ -d "$brain_home/fleet/agents/$ident" ]; then
-    ident_kind="seat"
-    idtok="$brain_home/fleet/agents/$ident/secrets/${idpfx}-${ident}.token"
-  else
-    ident_kind="service identity"
-    idtok="$svc_store/${idpfx}-${ident}.token"
-  fi
-  if [ -r "$idtok" ]; then
-    echo "username=${ident}"
-    echo "password=$(cat "$idtok")"
-    exit 0
-  fi
-fi
-
-# ── Shared-account fallback: ONLY on a host with no fleet and no identity ──────
-# `fleet/agents` existing is the same signal brain-home.ts uses to decide a brain
-# is active. Where there are seats, records must be attributable, so an
-# unresolvable request is refused instead of borrowing the shared account.
-fleet_present=0
-[ -d "$brain_home/fleet/agents" ] && fleet_present=1
-
-if [ -z "$ident" ] && [ "$fleet_present" -eq 0 ]; then
-  script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-  # shellcheck source=../_lib/credentials.sh
-  source "$script_dir/../_lib/credentials.sh"
-  load_credentials "$idpfx" >/dev/null 2>&1 || exit 0
-  # GITEA_USER is not populated by load_credentials (it exports GITEA_URL and
-  # GITEA_TOKEN only). Gitea's git-over-HTTP auth authenticates from the token in
-  # the password field, not from the username string, so any non-empty
-  # placeholder works — deliberately NOT a real account name, since framework
-  # files stay operator-agnostic (tools/quality/scripts/verify-sanitized.sh).
-  echo "username=${GITEA_USER:-git}"
-  echo "password=$GITEA_TOKEN"
-  exit 0
-fi
-
-# ── FAIL CLOSED ───────────────────────────────────────────────────────────────
-if [ -z "$ident" ]; then
-  reason="no-identity"
-else
-  reason="no-token-for-identity"
-fi
-
-seat="${MOSAIC_AGENT_NAME:-unknown}"
-ts=$(date -u +%Y-%m-%dT%H:%M:%SZ)
-
-# The escalation RECORD is durable and unconditional; any notification built on
-# top of it is best-effort. Record and alert are deduplicated separately — a cap
-# on the alert alone lets the spool grow without bound exactly while the operator
-# is being told nothing, so the louder the failure the quieter it gets.
-#
-# A record field is arbitrary operator-supplied text: an identity comes from git
-# config or the environment, and cwd is whatever directory git ran in. Either can
-# contain a quote or a backslash, which would make the line unparseable JSON --
-# and a spool that silently stops parsing is worse than no spool, because the
-# operator only discovers it while reading the record that explains an outage.
-json_escape() {
-  local s=$1
-  s=${s//\\/\\\\}
-  s=${s//\"/\\\"}
-  s=${s//$'\t'/\\t}
-  s=${s//$'\r'/\\r}
-  s=${s//$'\n'/\\n}
-  printf '%s' "$s"
-}
-
-spool="${MOSAIC_CREDENTIAL_SPOOL:-$HOME/.local/state/mosaic-credential-escalations}"
-spool_record=""
-if mkdir -p "$spool" 2>/dev/null; then
-  chmod 700 "$spool" 2>/dev/null
-  spoolfile="$spool/$(date -u +%Y%m%d).jsonl"
-  dedupe="$spool/.spooled-${seat}-${ident:-none}-${reason}-$(date -u +%Y%m%d%H%M)"
-  if [ ! -e "$dedupe" ]; then
-    : > "$dedupe" 2>/dev/null
-    printf '{"ts":"%s","reason":"%s","identity":"%s","identity_source":"%s","kind":"%s","seat":"%s","host":"%s","cwd":"%s"}\n' \
-      "$(json_escape "$ts")" "$(json_escape "$reason")" \
-      "$(json_escape "${ident:-<unset>}")" "$(json_escape "$ident_src")" \
-      "$(json_escape "${ident_kind:-none}")" "$(json_escape "$seat")" \
-      "$(json_escape "$host")" "$(json_escape "$PWD")" \
-      >> "$spoolfile" 2>/dev/null
-    chmod 600 "$spoolfile" 2>/dev/null
-  fi
-  # Name the record only if one is actually on disk. Printing the path
-  # unconditionally sends the operator to a file that does not exist on exactly
-  # the hosts where the spool could not be created.
-  [ -s "$spoolfile" ] && spool_record="$spoolfile"
-  find "$spool" -maxdepth 1 -name '.spooled-*' -mmin +120 -delete 2>/dev/null
-fi
-
-cat >&2 <<EOF
-git-credential-mosaic: REFUSED (fail-closed).
-  host     : ${host}
-  identity : ${ident:-<unset>}${ident:+  (from ${ident_src}; resolved as a ${ident_kind})}
-  reason   : ${reason}
-EOF
-
-if [ -n "$ident" ]; then
-  cat >&2 <<EOF
-  expected : ${idtok}
-EOF
-fi
-
-cat >&2 <<EOF
-
-No per-identity credential resolved. This helper does NOT fall back to the shared
-account: that fallback makes every record it creates attributable to one
-principal, which is unrecoverable once a pull request has merged under it.
-
-Fix (pick one):
-  export MOSAIC_GIT_IDENTITY=<agent-id>        # process-scoped
-  git config mosaic.gitIdentity <agent-id>     # per-repo/worktree, persists
-Then provision that identity's credential at the path named above. An identity
-with a directory under \${MOSAIC_BRAIN_HOME:-\$HOME/.mosaic}/fleet/agents/ is a
-seat and is read ONLY from its own secrets/ slot; any other identity is read from
-~/.config/mosaic/secrets/gitea-tokens/. There is no fallback between the two.
-
-If this identity legitimately needs git access and has none, ask the orchestrator
-to provision one.
-
-EOF
-
-if [ -n "$spool_record" ]; then
-  echo "  record: ${spool_record}" >&2
-else
-  echo "  record: NOT WRITTEN — spool unavailable at ${spool}" >&2
-fi
-exit 1

packages/mosaic/framework/tools/git/git-credential-mosaic.impl

@@ -0,0 +1,480 @@
+#!/bin/bash
+# git-credential-mosaic — git credential helper. Resolves a Gitea token from the
+# Mosaic credential store at runtime so remote URLs never embed secrets.
+#
+# Install (one-time, per clone or globally):
+#   git config credential.helper "$HOME/.config/mosaic/tools/git/git-credential-mosaic"
+#
+# Per-agent identity (Gate-16 author != reviewer separation):
+#   git config mosaic.gitIdentity <agent-id>   # per-worktree, persists on disk
+#   # or: export MOSAIC_GIT_IDENTITY=<agent-id>
+#
+# ── WHY THIS FAILS CLOSED ──────────────────────────────────────────────────────
+# This helper used to end by emitting the shared account's token for any request
+# it could not resolve to an identity. A seat with no identity, or with an
+# identity whose token was never provisioned, therefore received the most
+# privileged credential configured on the host — silently, and indistinguishably
+# from correct operation. Every record it then created (commit, push, PR, review)
+# was attributed to that shared account, so author != reviewer separation was
+# unenforceable and the true actor was unrecoverable after the fact.
+#
+# Under-provisioning must fail loudly, not impersonate. A refused git operation
+# is recoverable in one command; a merged pull request attributed to the wrong
+# principal is not.
+#
+# ── CONTRACT ───────────────────────────────────────────────────────────────────
+#   identity : MOSAIC_GIT_IDENTITY  >  git config mosaic.gitIdentity  >  the
+#              username git supplies on stdin
+#   ownership: a FLEET SEAT caller may resolve ONLY its own identity, where
+#              the CALLER is established by process ANCESTRY, not by the
+#              current environment: every ancestor's /proc/<pid>/environ is
+#              frozen at exec, so a child can rewrite its own MOSAIC_AGENT_NAME
+#              but can never make an ancestor disagree with what the launcher
+#              gave it (P5-RM-006; the dual-variable override was measured by
+#              rev-code-02 F1). An anonymous caller (no lineage, no consensus)
+#              may resolve NOTHING on a fleet host — seat or service
+#              (rev-code-02 F2). Non-fleet hosts keep the documented legacy
+#              paths below.
+#   perms    : a slot whose mode lets group or other read it (anything but
+#              ?00) is refused — a loose slot is provisioning drift, and
+#              serving from it silently widens every seat's exposure on a
+#              single-account host.
+#   store    : chosen by what the identity IS, with no precedence and no
+#              cross-store fallback (see "Credential store selection" below)
+#   hit      : emit username + password, exit 0
+#   miss     : emit NOTHING, spool a durable escalation record, explain on
+#              stderr, exit 1 — git surfaces the failure and nothing is attributed
+#   unknown host : exit 0 with no output, no record (passthrough for non-Mosaic
+#              remotes handled by another helper)
+#
+# Backward compatibility is preserved for exactly one case: a host with no fleet
+# and no identity requested still gets the shared account, because on such a host
+# the shared account is the operator's own and there is no attribution to lose.
+# A host that HAS a fleet has agents whose records must be distinguishable, so
+# the shared fallback is refused there.
+#
+# A token is never written to stderr, to the escalation record, or to any log.
+
+[ "$1" = "get" ] || exit 0
+
+
+# ── The shared refusal path ──────────────────────────────────────────────────
+# Every fail-closed exit funnels through refuse(): a durable escalation record
+# (deduped, JSON-escaped), a stderr diagnostic naming host/identity/reason,
+# caller-supplied guidance when the refusing site has specific advice, exit 1.
+# Defined here because the ownership gate below must be able to reach it.
+refuse() {
+  local guidance="${1:-}"
+  local seat ts spool spool_record spoolfile dedupe
+  seat="${MOSAIC_AGENT_NAME:-unknown}"
+  ts=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+
+  # A record field is arbitrary operator-supplied text: an identity comes from git
+  # config or the environment, and cwd is whatever directory git ran in. Either can
+  # contain a quote or a backslash, which would make the line unparseable JSON --
+  # and a spool that silently stops parsing is worse than no spool, because the
+  # operator only discovers it while reading the record that explains an outage.
+  json_escape() {
+    local s=$1
+    s=${s//\\/\\\\}
+    s=${s//\"/\\\"}
+    s=${s//$'\t'/\\t}
+    s=${s//$'\r'/\\r}
+    s=${s//$'\n'/\\n}
+    printf '%s' "$s"
+  }
+
+  spool="${MOSAIC_CREDENTIAL_SPOOL:-$HOME/.local/state/mosaic-credential-escalations}"
+  spool_record=""
+  if mkdir -p "$spool" 2>/dev/null; then
+    chmod 700 "$spool" 2>/dev/null
+    spoolfile="$spool/$(date -u +%Y%m%d).jsonl"
+    dedupe="$spool/.spooled-${seat}-${ident:-none}-${reason}-$(date -u +%Y%m%d%H%M)"
+    if [ ! -e "$dedupe" ]; then
+      : > "$dedupe" 2>/dev/null
+      printf '{"ts":"%s","reason":"%s","identity":"%s","identity_source":"%s","kind":"%s","seat":"%s","host":"%s","cwd":"%s"}\n' \
+        "$(json_escape "$ts")" "$(json_escape "$reason")" \
+        "$(json_escape "${ident:-<unset>}")" "$(json_escape "$ident_src")" \
+        "$(json_escape "${ident_kind:-none}")" "$(json_escape "$seat")" \
+        "$(json_escape "$host")" "$(json_escape "$PWD")" \
+        >> "$spoolfile" 2>/dev/null
+      chmod 600 "$spoolfile" 2>/dev/null
+    fi
+    # Name the record only if one is actually on disk. Printing the path
+    # unconditionally sends the operator to a file that does not exist on exactly
+    # the hosts where the spool could not be created.
+    [ -s "$spoolfile" ] && spool_record="$spoolfile"
+    find "$spool" -maxdepth 1 -name '.spooled-*' -mmin +120 -delete 2>/dev/null
+  fi
+
+  while IFS= builtin read -r _diag_line; do builtin printf '%s\n' "$_diag_line" >&2; done <<EOF
+git-credential-mosaic: REFUSED (fail-closed).
+  host     : ${host}
+  identity : ${ident:-<unset>}${ident:+  (from ${ident_src}; resolved as a ${ident_kind})}
+  reason   : ${reason}
+EOF
+
+  if [ -n "$ident" ]; then
+    while IFS= builtin read -r _diag_line; do builtin printf '%s\n' "$_diag_line" >&2; done <<EOF
+  expected : ${idtok}
+EOF
+  fi
+
+  while IFS= builtin read -r _diag_line; do builtin printf '%s\n' "$_diag_line" >&2; done <<EOF
+
+${guidance}
+EOF
+
+  if [ -n "$spool_record" ]; then
+    echo "  record: ${spool_record}" >&2
+  else
+    echo "  record: NOT WRITTEN — spool unavailable at ${spool}" >&2
+  fi
+  exit 1
+}
+
+# ── Bash environment injection guard (rev-code-02 R3, B1) ───────────────────
+# Non-interactive bash sources $BASH_ENV at startup and imports exported
+# functions from BASH_FUNC_* environment entries; either can define a read()
+# or printf() that shadows the builtin the ancestry walker and diagnostics
+# rely on — measured live by the reviewer's fixture (BASH_ENV read() rewrote
+# every ancestry entry). A legitimate fleet seat environment carries neither
+# (verified: zero BASH_FUNC_* in seat envs), so their presence in a helper
+# request is an injection attempt: scrub the shadows first (so even the
+# refusal machinery cannot be subverted), then refuse fail-closed.
+# Imported functions are detected by ENUMERATION, not env-var names: bash
+# consumes BASH_FUNC_* variables while importing the functions, so the
+# environment no longer shows them (measured). At this point the script has
+# defined exactly one function of its own (refuse); anything else in the
+# function table arrived from the caller's environment. BASH_ENV is checked
+# directly (it remains visible after sourcing).
+_injected=0
+_inj_names=""
+while IFS=' ' builtin read -r _decl _kind _fn; do
+  [ -n "$_fn" ] || continue
+  case "$_fn" in
+    refuse) ;;
+    *) _injected=1; _inj_names="$_inj_names $_fn";;
+  esac
+done < <(declare -F)
+_inj_vars="${!BASH_FUNC_@}"
+if [ -n "$_inj_vars" ]; then
+  _injected=1
+  for _iv in $_inj_vars; do
+    case "$_iv" in
+      BASH_FUNC_*%%) _ifn="${_iv#BASH_FUNC_}"; _ifn="${_ifn%%%}";;
+      BASH_FUNC_*)   _ifn="${_iv#BASH_FUNC_}";;
+      *)             _ifn="";;
+    esac
+    [ -n "$_ifn" ] && { unset -f "$_ifn" 2>/dev/null; _inj_names="$_inj_names $_ifn"; }
+  done
+fi
+if [ "$_injected" = 1 ] || [ -n "${BASH_ENV:-}" ]; then
+  while IFS=' ' builtin read -r _decl _kind _fn; do
+    [ "$_fn" = refuse ] || unset -f "$_fn" 2>/dev/null
+  done < <(declare -F)
+  unset BASH_ENV 2>/dev/null
+  reason="bash-environment-injection-refused"
+  refuse "The helper's bash startup state was externally shaped: BASH_ENV is
+set and/or exported BASH_FUNC_* functions are present in the request
+environment. Non-interactive bash sources BASH_ENV and imports those
+functions BEFORE any script line runs, so builtins this helper's security
+decisions rely on could be shadowed. Nothing resolves from a shaped request
+environment. If this surprised a legitimate workflow, the caller environment
+must be cleaned (no BASH_ENV, no exported functions) before invoking git."
+fi
+
+
+host=""; username_in=""
+while IFS= builtin read -r line; do
+  [ -z "$line" ] && break
+  case "$line" in
+    host=*)     host=${line#host=};;
+    username=*) username_in=${line#username=};;
+  esac
+done
+
+# Recognized Gitea hosts carry the per-identity token scheme. Anything else is
+# declined quietly — another helper owns it, and refusing would break it.
+case "$host" in
+  git.uscllc.com)      idpfx=gitea-usc;;
+  git.mosaicstack.dev) idpfx=gitea-mosaicstack;;
+  *) exit 0;;
+esac
+
+# ── Clean-entrypoint assert (P0-SEC R4) ─────────────────────────────────────
+# This implementation only runs behind the python entrypoint
+# (git-credential-mosaic), which execve's it with an allowlist environment:
+# no BASH_ENV, no imported functions, nothing shapable at bash startup. A
+# direct invocation without the marker is a bypass attempt on that boundary
+# and refuses. Placed after refuse() and the host parse so the refusal path
+# exists when it fires (an earlier placement died on 'refuse: command not
+# found' — the failure mode is real, keep this after every definition it
+# calls).
+if [ "${_MOSAIC_HELPER_CLEAN:-}" != "1" ]; then
+  reason="direct-entrypoint-refused"
+  refuse "This implementation refuses to run outside the production
+entrypoint. git-credential-mosaic (the python wrapper in this directory)
+execve's it with a hand-built, unshapable environment; invoking the .impl
+directly bypasses that boundary. Credential requests go through git, which
+invokes the wrapper named in gitconfig."
+fi
+
+ident="$MOSAIC_GIT_IDENTITY"; ident_src="MOSAIC_GIT_IDENTITY"
+if [ -z "$ident" ]; then
+  ident=$(git config --get mosaic.gitIdentity 2>/dev/null)
+  ident_src="git config mosaic.gitIdentity"
+fi
+if [ -z "$ident" ]; then
+  ident="$username_in"
+  ident_src="the username git supplied"
+fi
+
+# ── Credential store selection ────────────────────────────────────────────────
+# An identity is a SEAT or it is a SERVICE, and which one it is determines where
+# its credential lives. There is no precedence rule between the two stores and no
+# fallback from one to the other: a seat whose slot is empty fails closed rather
+# than reading a service credential that happens to share its name.
+#
+#   seat     — <brain>/fleet/agents/<ident>/ exists
+#              credential at <brain>/fleet/agents/<ident>/secrets/<idpfx>-<ident>.token
+#   service  — it does not
+#              credential at ~/.config/mosaic/secrets/gitea-tokens/<idpfx>-<ident>.token
+#
+# One credential, one location. Two copies of one credential diverge, and the
+# stale copy fails in a way that reads as a revoked token rather than as drift.
+#
+# Brain-home resolution mirrors packages/mosaic/src/fleet/brain-home.ts and
+# tools/fleet/start-agent-session.sh: MOSAIC_BRAIN_HOME wins, else ~/.mosaic.
+brain_home="${MOSAIC_BRAIN_HOME:-$HOME/.mosaic}"
+svc_store="$HOME/.config/mosaic/secrets/gitea-tokens"
+
+# ── Caller-identity ownership (P5-RM-006) ──────────────────────────────────────
+# A credential request is honourable only when the CALLER owns the identity it
+# asks for. On a fleet host every seat shares one unix account, so the
+# launcher-established MOSAIC_AGENT_NAME is the only attribution signal the
+# helper has. Two measured paths made the old contract unsafe:
+#
+#   - a seat exporting MOSAIC_GIT_IDENTITY=<another-seat> resolved that seat's
+#     token through the normal precedence chain (T97 G2, jarvis V2 probe), and
+#   - an anonymous caller (no seat name) inherited the host gitconfig's
+#     username=jarvis line and resolved jarvis's slot (T94: five watcher units
+#     flapping on exactly this class).
+#
+# Ownership rules, fail-closed on fleet hosts only; a host with no fleet keeps
+# the legacy contract unchanged:
+#   1. a SEAT caller may resolve only its own identity;
+#   2. an anonymous caller may not resolve any SEAT identity (service
+#      identities remain available to non-seat automation such as CI).
+# [P5-RM-006r1 ancestry binding begin]
+# ── Caller identity from exec-frozen ancestry (rev-code-02 F1/F2) ───────────
+# Walk /proc self->root collecting MOSAIC_AGENT_NAME from each ancestor's
+# frozen environ. Rules:
+#   - any DISAGREEMENT (an ancestor value != the current value, or ancestors
+#     disagreeing among themselves) is a rewrite -> spoof-refused, nothing
+#     resolves. A child can inject variables downward but cannot alter an
+#     ancestor's exec-frozen environ, so the launcher-established value always
+#     participates in the comparison.
+#   - consensus (all ancestors that carry the var agree with the current env,
+#     or with each other when the current env is empty) -> caller = that value.
+#   - no ancestor carries it -> the current claim is unlineaged: caller is
+#     anonymous regardless of what the environment says. A name with no
+#     lineage is a claim, not an identity.
+# The walk stops at PID 1, at a missing /proc entry, or INCLUSIVE at an
+# ancestor that carries MOSAIC_CREDENTIAL_LINEAGE_FENCE with an EMPTY agent
+# name — the test-suite lineage root. A fence beside a non-empty name is
+# IGNORED and the walk continues, so an attacker cannot fence off the true
+# ancestry by planting the marker next to a victim name.
+trusted_caller() {
+  # PATH-HARDENED (rev-code-02 R1 F1): every /proc read below uses ONLY bash
+  # builtins (read/case/parameter expansion). The first implementation piped
+  # through PATH-resolved tr/sed/head/grep, and a caller that prepends hostile
+  # utilities to PATH in the same invocation that overrides the identity
+  # variables could forge the ancestry itself. Builtins cannot be shadowed.
+  local pid ppid v entry line fence
+  local -a vals=()
+  pid=$$
+  while :; do
+    v=""
+    fence=0
+    if [ -r "/proc/$pid/environ" ]; then
+      # Read inside a captured subshell whose stderr is closed: opening
+      # /proc/<pid>/environ can fail with EACCES on ancestors that are
+      # readable-by-mode but not openable (session managers), and that open
+      # failure prints from the SHELL, immune to loop-level 2>/dev/null
+      # (measured). The subshell makes the skip silent; NUL separators are
+      # converted to newlines for the parent's builtin parse.
+      _env_text=$( { while IFS= builtin read -r -d '' _e; do builtin printf '%s\n' "$_e"; done < "/proc/$pid/environ"; } 2>/dev/null )
+      while IFS= builtin read -r entry; do
+        [ -n "$entry" ] || continue
+        case "$entry" in
+          MOSAIC_AGENT_NAME=*) v="${entry#MOSAIC_AGENT_NAME=}";;
+          MOSAIC_CREDENTIAL_LINEAGE_FENCE=*) fence=1;;
+        esac
+      done <<EOF_ENV
+$_env_text
+EOF_ENV
+    fi
+    if [ "$pid" != "$$" ]; then
+      [ -n "$v" ] && vals+=("$v")
+      if [ "$fence" = 1 ] && [ -z "$v" ]; then
+        break
+      fi
+    fi
+    ppid=""
+    if [ -r "/proc/$pid/status" ]; then
+      while IFS= builtin read -r line; do
+        case "$line" in
+          PPid:*) ppid="${line#PPid:}"; ppid="${ppid//[[:space:]]/}";;
+        esac
+      done < "/proc/$pid/status"
+    fi
+    case "$ppid" in ''|0|1) break;; esac
+    pid=$ppid
+  done
+  local self="${MOSAIC_AGENT_NAME:-}" i consensus=""
+  if [ "${#vals[@]}" -gt 0 ]; then
+    consensus="${vals[0]}"
+    for i in "${vals[@]}"; do
+      if [ "$i" != "$consensus" ]; then
+        printf 'SPOOF'
+        return
+      fi
+    done
+    if [ -n "$self" ] && [ "$self" != "$consensus" ]; then
+      printf 'SPOOF'
+      return
+    fi
+  fi
+  printf '%s' "$consensus"
+}
+
+if [ -d "$brain_home/fleet/agents" ]; then
+  caller="$(trusted_caller)"
+  if [ "$caller" = "SPOOF" ]; then
+    reason="caller-identity-spoof-refused"
+    refuse "The MOSAIC_AGENT_NAME lineage disagrees within this process tree:
+an ancestor established by exec carries a different value than the request.
+A child process can rewrite its own environment but never an ancestor's
+frozen environ, so disagreement is a rewrite, not a race. Nothing resolves
+under a rewritten caller identity. If this surprised a legitimate workflow,
+run git from the seat's own session, not from a rewritten environment."
+  fi
+  if [ -n "$caller" ] && [ -d "$brain_home/fleet/agents/$caller" ]; then
+    if [ -n "$ident" ] && [ "$ident" != "$caller" ]; then
+      reason="cross-seat-identity-refused"
+      refuse "A seat may resolve only its own credential slot. Caller seat is
+'$caller' (ancestry-established); the request names '$ident'. Overriding
+MOSAIC_GIT_IDENTITY (or a git config / URL username) to another seat's name is
+exactly the path this refusal exists to close. If '$ident' auth is genuinely
+required, that seat runs the operation itself or the orchestrator provisions
+an explicit grant."
+    fi
+  else
+    # Anonymous caller on a fleet host (no lineage, or the lineage root is not
+    # a seat): NOTHING resolves — seat slots (T94 jarvis@ class) or legacy
+    # service credentials (rev-code-02 F2: credentialed services are seats;
+    # the legacy store is vestigial and not anonymously reachable).
+    if [ -n "$ident" ]; then
+      ident_kind="${ident_kind:-}"
+      [ -d "$brain_home/fleet/agents/$ident" ] && ident_kind="seat" || ident_kind="service identity"
+      reason="anonymous-credential-refused"
+      refuse "This caller has no seat lineage on a fleet host and asked for
+'$ident' (a ${ident_kind}). Anonymous callers resolve nothing on fleet hosts:
+seat credentials must never serve an unattributable caller, and credentialed
+services are seats with their own sessions (the legacy service store is
+vestigial). Run from the owning seat's session."
+    fi
+  fi
+fi
+# [P5-RM-006r1 ancestry binding end]
+
+idtok=""; ident_kind=""
+if [ -n "$ident" ]; then
+  if [ -d "$brain_home/fleet/agents/$ident" ]; then
+    ident_kind="seat"
+    idtok="$brain_home/fleet/agents/$ident/secrets/${idpfx}-${ident}.token"
+  else
+    ident_kind="service identity"
+    idtok="$svc_store/${idpfx}-${ident}.token"
+  fi
+  if [ -r "$idtok" ]; then
+    # P5-RM-006 seat permissions: a SEAT slot readable by group or other is
+    # provisioning drift, and on a single-account fleet host it widens every
+    # seat's exposure at once. Refuse rather than serve from a loose slot; the
+    # record names the path so the provisioning fix is one chmod away.
+    # Scoped to seat slots: the framework service store is operator-managed
+    # and outside this work unit's permission surface.
+    if [ "${ident_kind:-}" = "seat" ]; then
+      # command -p resolves stat from the POSIX default PATH (system
+      # directories), never the caller's PATH (rev-code-02 R3 B2: a shadowed
+      # stat reported a 0644 slot as 600 and the helper served it). Output is
+      # shape-validated: anything that is not 3-4 octal digits refuses.
+      slot_mode="$(command -p stat -c '%a' "$idtok" 2>/dev/null || true)"
+      case "$slot_mode" in
+        [0-7][0-7][0-7]|[0-7][0-7][0-7][0-7]) ;;
+        *) slot_mode="unverifiable";;
+      esac
+      if [ "${slot_mode:1:2}" != "00" ]; then
+        reason="slot-permission-violation"
+        refuse "Slot $idtok has mode ${slot_mode:-unknown}; expected owner-only
+(0600 or stricter). Tighten it: chmod 600 '$idtok'. This refusal is the seat
+permissions half of P5-RM-006: a loose slot on a shared-account host is every
+seat's exposure, so the helper declines to serve from it. Mode inspection uses
+command -p (trusted PATH) and fails closed on unverifiable output."
+      fi
+    fi
+    echo "username=${ident}"
+    echo "password=$(<"$idtok")"
+    exit 0
+  fi
+fi
+
+# ── Shared-account fallback: ONLY on a host with no fleet and no identity ──────
+# `fleet/agents` existing is the same signal brain-home.ts uses to decide a brain
+# is active. Where there are seats, records must be attributable, so an
+# unresolvable request is refused instead of borrowing the shared account.
+fleet_present=0
+[ -d "$brain_home/fleet/agents" ] && fleet_present=1
+
+if [ -z "$ident" ] && [ "$fleet_present" -eq 0 ]; then
+  script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+  # shellcheck source=../_lib/credentials.sh
+  source "$script_dir/../_lib/credentials.sh"
+  load_credentials "$idpfx" >/dev/null 2>&1 || exit 0
+  # GITEA_USER is not populated by load_credentials (it exports GITEA_URL and
+  # GITEA_TOKEN only). Gitea's git-over-HTTP auth authenticates from the token in
+  # the password field, not from the username string, so any non-empty
+  # placeholder works — deliberately NOT a real account name, since framework
+  # files stay operator-agnostic (tools/quality/scripts/verify-sanitized.sh).
+  echo "username=${GITEA_USER:-git}"
+  echo "password=$GITEA_TOKEN"
+  exit 0
+fi
+
+# ── FAIL CLOSED ───────────────────────────────────────────────────────────────
+# The escalation RECORD is durable and unconditional; any notification built on
+# top of it is best-effort (see refuse()). Record and alert are deduplicated
+# separately — a cap on the alert alone lets the spool grow without bound
+# exactly while the operator is being told nothing, so the louder the failure
+# the quieter it gets.
+if [ -z "$ident" ]; then
+  reason="no-identity"
+else
+  reason="no-token-for-identity"
+fi
+refuse "No per-identity credential resolved. This helper does NOT fall back to the shared
+account: that fallback makes every record it creates attributable to one
+principal, which is unrecoverable once a pull request has merged under it.
+
+Fix (pick one):
+  export MOSAIC_GIT_IDENTITY=<agent-id>        # process-scoped
+  git config mosaic.gitIdentity <agent-id>     # per-repo/worktree, persists
+Then provision that identity's credential at the path named above. An identity
+with a directory under \${MOSAIC_BRAIN_HOME:-\$HOME/.mosaic}/fleet/agents/ is a
+seat and is read ONLY from its own secrets/ slot; any other identity is read from
+~/.config/mosaic/secrets/gitea-tokens/. There is no fallback between the two.
+
+If this identity legitimately needs git access and has none, ask the orchestrator
+to provision one."
+

packages/mosaic/framework/tools/git/test-git-credential-mosaic.sh

@@ -34,20 +34,23 @@ REPO_DIR="$WORK_DIR/repo"
 BRAIN_DIR="$WORK_DIR/brain"
 SPOOL_DIR="$WORK_DIR/spool"
 SVC_STORE="$FAKE_HOME/.config/mosaic/secrets/gitea-tokens"
-# Mirror the real deployed layout (~/.config/mosaic/tools/{git,_lib}/) under the
+# Mirror the real deployed layout (~/.mosaic/tools/{git,_lib}/) under the
 # fake HOME: git-credential-mosaic resolves its credentials.sh sibling via a
 # script-relative path (BASH_SOURCE), so the copy must live next to a stubbed
 # _lib/credentials.sh, not the real one, to keep this test hermetic.
-HELPER="$FAKE_HOME/.config/mosaic/tools/git/git-credential-mosaic"
+HELPER="$FAKE_HOME/.mosaic/tools/git/git-credential-mosaic"
+IMPL="$FAKE_HOME/.mosaic/tools/git/git-credential-mosaic.impl"
 
 rm -rf "$WORK_DIR"
 mkdir -p "$SVC_STORE" \
-         "$FAKE_HOME/.config/mosaic/tools/git" \
+         "$FAKE_HOME/.mosaic/tools/git" \
-         "$FAKE_HOME/.config/mosaic/tools/_lib" \
+         "$FAKE_HOME/.mosaic/tools/_lib" \
          "$REPO_DIR" "$BRAIN_DIR"
 
 cp "$SCRIPT_DIR/git-credential-mosaic" "$HELPER"
 chmod +x "$HELPER"
+cp "$SCRIPT_DIR/git-credential-mosaic.impl" "$IMPL"
+chmod +x "$IMPL"
 
 git -C "$REPO_DIR" init -q
 git -C "$REPO_DIR" config user.email "[email protected]"
@@ -55,7 +58,7 @@ git -C "$REPO_DIR" config user.name "Test"
 
 # Fake shared-account credential loader — stands in for
 # tools/_lib/credentials.sh's load_credentials(), scoped to this test only.
-cat > "$FAKE_HOME/.config/mosaic/tools/_lib/credentials.sh" <<'SH'
+cat > "$FAKE_HOME/.mosaic/tools/_lib/credentials.sh" <<'SH'
 load_credentials() {
   case "$1" in
     gitea-mosaicstack) GITEA_URL="https://git.mosaicstack.dev"; GITEA_TOKEN="shared-mosaicstack-token"; export GITEA_URL GITEA_TOKEN; return 0 ;;
@@ -82,7 +85,7 @@ run_helper() {
   (
     cd "$REPO_DIR"
     env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$SPOOL_DIR" "$@" \
-      bash "$HELPER" get <<EOF
+      "$HELPER" get <<EOF
 host=$host
 username=$username_in
 
@@ -90,6 +93,80 @@ EOF
   )
 }
 
+# ── Lineage harness (rev-code-02 F1/F2 rework) ─────────────────────────────
+# Establishes a seat CALLER the way production does — frozen into an
+# ancestor's exec environment — instead of injecting MOSAIC_AGENT_NAME into
+# the helper's own env. Two scripts are generated into WORK_DIR:
+#
+#   lineage-root.sh  (pid A): invoked with a fence marker and NO agent name.
+#       With a non-empty caller arg it forks the carrier (pid C); with an
+#       empty caller it forks the helper directly (deterministic anonymous
+#       lineage even when the suite itself runs inside a seat).
+#   lineage-carrier.sh (pid C): MOSAIC_AGENT_NAME=<caller> frozen at exec;
+#       forks the helper (pid D) with a fully controlled env.
+#
+# The helper's walk then sees exactly: self -> C(caller) or D-direct ->
+# A(fence, empty name -> stop). EXTRA assignments ride pid D's environment
+# (that is where a rewrite would live — which is the point of the F1 arms).
+cat > "$WORK_DIR/lineage-root.sh" <<'LINROOT'
+#!/usr/bin/env bash
+# pid A — lineage root. Args: <caller> <carrier-script> <helper> <spool>
+# <brain> <repo> [extra KEY=VALUE...]
+set -u
+caller="$1"; carrier="$2"; helper="$3"; spool="$4"; brain="$5"; repo="$6"; shift 6
+if [ -n "$caller" ]; then
+  env MOSAIC_AGENT_NAME="$caller" PATH="$PATH" HOME="$HOME" \
+    bash "$carrier" "$helper" "$spool" "$brain" "$repo" "$@"
+else
+  env -i HOME="$HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$spool" \
+       MOSAIC_BRAIN_HOME="$brain" "$@" "$helper" get
+fi
+LINROOT
+cat > "$WORK_DIR/lineage-carrier.sh" <<'LINCARR'
+#!/usr/bin/env bash
+# pid C — the caller's frozen environment. Forks the helper (pid D).
+set -u
+helper="$1"; spool="$2"; brain="$3"; repo="$4"; shift 4
+cd "$repo"
+env -i HOME="$HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$spool" \
+     MOSAIC_BRAIN_HOME="$brain" "$@" "$helper" get
+LINCARR
+chmod +x "$WORK_DIR/lineage-root.sh" "$WORK_DIR/lineage-carrier.sh"
+
+run_lineage() {
+  # run_lineage <caller|empty-for-anonymous> [helper-env KEY=VALUE...]
+  local caller="$1"; shift
+  printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+    env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_LINEAGE_FENCE=1 \
+      bash "$WORK_DIR/lineage-root.sh" "$caller" "$WORK_DIR/lineage-carrier.sh" \
+      "$HELPER" "$SPOOL_DIR" "$BRAIN_DIR" "$REPO_DIR" "$@"
+}
+
+assert_refused_lineage() {
+  # assert_refused_lineage <desc> <caller> <want-reason> [helper-env...]
+  local desc="$1" caller="$2" want="$3"; shift 3
+  local stderr_file="$WORK_DIR/stderr-lin.tmp" rc stdout
+  : > "$stderr_file"
+  set +e
+  stdout=$(run_lineage "$caller" "$@" 2>"$stderr_file")
+  rc=$?
+  set -e
+  local stderr; stderr=$(cat "$stderr_file")
+  if [[ "$rc" -eq 0 ]]; then
+    echo "FAIL: $desc — expected nonzero exit, got 0 (stdout='$stdout')" >&2; fail=1
+  fi
+  if [[ -n "$stdout" ]]; then
+    echo "FAIL: $desc — expected empty stdout, got '$stdout'" >&2; fail=1
+  fi
+  if [[ -n "$want" && "$stderr" != *"$want"* ]]; then
+    echo "FAIL: $desc — stderr lacks '$want':" >&2; echo "$stderr" >&2; fail=1
+  fi
+  if [[ "$stdout$stderr" == *"seatG-slot-token"* || "$stdout$stderr" == *"seatE-slot-token"* \
+     || "$stdout$stderr" == *"shared-mosaicstack-token"* || "$stdout$stderr" == *"shared-usc-token"* ]]; then
+    echo "FAIL: $desc — a slot or shared token VALUE appeared in output" >&2; fail=1
+  fi
+}
+
 # A refusal must be observable in four independent ways: nonzero exit, EMPTY
 # stdout, a stderr diagnostic naming the identity and host, and — the assertion
 # that actually catches a regression to the old behavior — NO shared token value
@@ -222,7 +299,10 @@ fi
 # ---------------------------------------------------------------------------
 mkdir -p "$BRAIN_DIR/fleet/agents/seatE/secrets"
 echo -n "seatE-slot-token" > "$BRAIN_DIR/fleet/agents/seatE/secrets/gitea-mosaicstack-seatE.token"
-out=$(run_helper "git.mosaicstack.dev" "seatE" MOSAIC_BRAIN_HOME="$BRAIN_DIR")
+chmod 600 "$BRAIN_DIR/fleet/agents/seatE/secrets/gitea-mosaicstack-seatE.token"
+# Seat arms run through the lineage harness below (rev-code-02 F1/F2 rework):
+# a seat caller must be established by ancestry, not by the helper's own env.
+out=$(run_lineage seatE MOSAIC_AGENT_NAME=seatE MOSAIC_GIT_IDENTITY=seatE)
 assert_eq "seat reads its own slot: username" "username=seatE" "$(echo "$out" | grep '^username=')"
 assert_eq "seat reads its own slot: password" "password=seatE-slot-token" "$(echo "$out" | grep '^password=')"
 
@@ -236,8 +316,8 @@ assert_eq "seat reads its own slot: password" "password=seatE-slot-token" "$(ech
 # ---------------------------------------------------------------------------
 mkdir -p "$BRAIN_DIR/fleet/agents/seatF/secrets"
 echo -n "seatF-SERVICE-STORE-token" > "$SVC_STORE/gitea-mosaicstack-seatF.token"
-assert_fail_closed "seat with empty slot does NOT fall back to the framework store" \
+assert_refused_lineage "seat with empty slot does NOT fall back to the framework store" \
-  "git.mosaicstack.dev" "seatF" "fleet/agents/seatF/secrets" MOSAIC_BRAIN_HOME="$BRAIN_DIR"
+  seatF no-token-for-identity MOSAIC_AGENT_NAME=seatF MOSAIC_GIT_IDENTITY=seatF
 : > "$WORK_DIR/stderr.tmp"
 set +e
 xstore_out=$(run_helper "git.mosaicstack.dev" "seatF" MOSAIC_BRAIN_HOME="$BRAIN_DIR" 2>"$WORK_DIR/stderr.tmp")
@@ -288,7 +368,7 @@ assert_eq "unknown host on a fleet host: still passthrough, not a refusal" "" "$
 # 13. Non-"get" verb (store/erase) -> exit 0, no output (git-credential
 #     protocol: this helper only implements get).
 # ---------------------------------------------------------------------------
-store_out=$(cd "$REPO_DIR" && env -i HOME="$FAKE_HOME" PATH="$PATH" bash "$HELPER" store <<EOF
+store_out=$(cd "$REPO_DIR" && env -i HOME="$FAKE_HOME" PATH="$PATH" "$HELPER" store <<EOF
 host=git.mosaicstack.dev
 username=no-such-agent
 password=whatever
@@ -310,7 +390,7 @@ hostile_spool="$WORK_DIR/spool-hostile"
   cd "$hostile_dir"
   env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$hostile_spool" \
     MOSAIC_GIT_IDENTITY=no-such-agent \
-    bash "$HELPER" get <<EOF >/dev/null 2>&1
+    "$HELPER" get <<EOF >/dev/null 2>&1
 host=git.mosaicstack.dev
 username=no-such-agent
 
@@ -349,7 +429,7 @@ nospool_err=$(
   cd "$REPO_DIR"
   env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$unwritable_spool" \
     MOSAIC_GIT_IDENTITY=no-such-agent \
-    bash "$HELPER" get <<EOF 2>&1 >/dev/null
+    "$HELPER" get <<EOF 2>&1 >/dev/null
 host=git.mosaicstack.dev
 username=no-such-agent
 
@@ -365,6 +445,193 @@ if [[ "$nospool_err" != *"NOT WRITTEN"* ]]; then
   fail=1
 fi
 
+# ---------------------------------------------------------------------------
+# 11. P5-RM-006 (+r1 rework) — caller identity from exec-frozen ancestry.
+#    A seat caller is established by lineage, not by the helper's own env;
+#    disagreement anywhere in the lineage is a rewrite and refuses; an
+#    anonymous caller resolves NOTHING on a fleet host (seat or service);
+#    a loose seat-slot mode refuses. Enforcement-removal red control at 11h.
+# ---------------------------------------------------------------------------
+mkdir -p "$BRAIN_DIR/fleet/agents/seatG/secrets"
+echo -n "seatG-slot-token" > "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+chmod 600 "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+
+# 11a. Cross-seat negative (lineage seatE, env ident=seatG): still refused.
+assert_refused_lineage "seat cannot override identity to another seat's slot" \
+  seatE cross-seat-identity-refused MOSAIC_GIT_IDENTITY=seatG
+
+# 11b. Seat asking for a SERVICE identity: cross-seat territory.
+assert_refused_lineage "seat cannot resolve a service identity either" \
+  seatE cross-seat-identity-refused MOSAIC_GIT_IDENTITY=agentA
+
+# 11c. Anonymous caller asking for a seat slot is refused.
+assert_refused_lineage "anonymous caller cannot resolve a seat slot on a fleet host" \
+  "" anonymous-credential-refused MOSAIC_GIT_IDENTITY=seatG
+
+# 11d. Anonymous caller asking for a SERVICE identity: ALSO refused
+#     (rev-code-02 F2 — credentialed services are seats; the legacy store is
+#     not anonymously reachable on fleet hosts).
+assert_refused_lineage "anonymous caller cannot resolve a legacy service credential either" \
+  "" anonymous-credential-refused MOSAIC_GIT_IDENTITY=agentA
+
+# 11e. Slot permissions: a group-readable slot is refused; mode restored -> serves.
+chmod 644 "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+assert_refused_lineage "loose slot mode is refused" \
+  seatG slot-permission-violation MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG
+chmod 600 "$BRAIN_DIR/fleet/agents/seatG/secrets/gitea-mosaicstack-seatG.token"
+out=$(run_lineage seatG MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG)
+assert_eq "mode restored to 600: seatG serves again" "password=seatG-slot-token" "$(echo "$out" | grep '^password=')"
+
+# 11f. rev-code-02 F1 repro: dual-variable override (caller lineage seatE,
+#     helper env carrying MOSAIC_AGENT_NAME=seatG AND MOSAIC_GIT_IDENTITY=seatG).
+assert_refused_lineage "F1: dual MOSAIC_AGENT_NAME+MOSAIC_GIT_IDENTITY override refused" \
+  seatE caller-identity-spoof-refused MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG
+
+# 11g. Stripped lineage still serves the rightful seat: caller frozen at the
+#     ancestor, helper env clean (self empty), own ident.
+out=$(run_lineage seatE MOSAIC_GIT_IDENTITY=seatE)
+assert_eq "lineage consensus with stripped self still serves the owning seat" \
+  "password=seatE-slot-token" "$(echo "$out" | grep '^password=')"
+
+# 11h. RED CONTROL: delete the ancestry binding between markers from a copy
+#     of the IMPLEMENTATION (run directly with the clean marker — a red control
+#     measures the binding itself, deliberately not through the wrapper);
+#     the F1 dual-override request must then RESOLVE seatG's token — the
+#     exact measured failure — proving the binding is the enforcement.
+RED_HELPER="$WORK_DIR/red/git-credential-mosaic.impl"
+mkdir -p "$WORK_DIR/red"
+sed '/P5-RM-006r1 ancestry binding begin/,/P5-RM-006r1 ancestry binding end/d' "$IMPL" > "$RED_HELPER"
+chmod +x "$RED_HELPER"
+if cmp -s "$IMPL" "$RED_HELPER"; then
+  echo "FAIL: red control is vacuous — marker deletion removed nothing" >&2
+  fail=1
+fi
+set +e
+red_out=$(printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+  env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_LINEAGE_FENCE=1 \
+    bash "$WORK_DIR/lineage-root.sh" seatE "$WORK_DIR/lineage-carrier.sh" \
+      "$RED_HELPER" "$SPOOL_DIR" "$BRAIN_DIR" "$REPO_DIR" \
+      _MOSAIC_HELPER_CLEAN=1 MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG 2>/dev/null)
+set -e
+if [[ "$(echo "$red_out" | grep '^password=')" != "password=seatG-slot-token" ]]; then
+  echo "FAIL: red control — with the binding removed, the F1 dual-override should have resolved seatG's token, got: $red_out" >&2
+  fail=1
+else
+  echo "ok: red control — binding removed -> F1 dual-override resolves the victim token (the binding is the enforcement)"
+fi
+
+# 11h2. rev-code-02 R1 F1: PATH-shadowed tr/sed/head/grep must not forge the
+#      ancestry. The dual-override request runs with a hostile PATH whose
+#      utilities claim the victim name for every /proc read; the walker uses
+#      only bash builtins, so the shadows never execute and the refusal holds.
+HOSTILE_BIN="$WORK_DIR/hostile-bin"
+mkdir -p "$HOSTILE_BIN"
+for tool in tr sed head grep cat stat; do
+  printf '#!/usr/bin/env bash\ncat >/dev/null\necho "MOSAIC_AGENT_NAME=seatG"\nexit 0\n' > "$HOSTILE_BIN/$tool"
+  chmod +x "$HOSTILE_BIN/$tool"
+done
+assert_refused_lineage "F1-R1: hostile PATH utilities cannot forge ancestry (dual override still refused)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG PATH="$HOSTILE_BIN:$PATH"
+
+# 11i. Service automation integration arm (rev-code-02 R2 bar): a SERVICE
+#      seat bound by lineage resolves its own slot — the brain-git-sync shape.
+mkdir -p "$BRAIN_DIR/fleet/agents/svc-fixture/secrets"
+echo -n "svc-fixture-slot-token" > "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+chmod 600 "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+out=$(run_lineage svc-fixture MOSAIC_AGENT_NAME=svc-fixture MOSAIC_GIT_IDENTITY=svc-fixture)
+assert_eq "service automation with bound seat lineage resolves its own slot" \
+  "password=svc-fixture-slot-token" "$(echo "$out" | grep '^password=')"
+
+# 11j. rev-code-02 R3 B1: BASH_ENV shaping. A read() shadow defined through
+#      BASH_ENV must be refused before any resolution — the guard scrubs and
+#      refuses with bash-environment-injection-refused.
+INJ_SH="$WORK_DIR/inj-read.sh"
+printf 'read() { builtin read -r _x || return 0; printf "MOSAIC_AGENT_NAME=seatG\\n"; return 0; }\n' > "$INJ_SH"
+assert_refused_lineage "F1-R3: BASH_ENV read() shadow is dropped at the wrapper boundary (identity gate governs)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG BASH_ENV="$INJ_SH"
+
+# 11k. rev-code-02 R3 B1: exported functions (BASH_FUNC_* import) refused too.
+assert_refused_lineage "F1-R3: exported BASH_FUNC_* import never crosses the wrapper boundary (identity gate governs)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG \
+  'BASH_FUNC_read%%=() { builtin read -r _x || return 0; printf "MOSAIC_AGENT_NAME=seatG\\n"; return 0; }'
+
+# 11l. rev-code-02 R3 B2: hostile stat cannot launder a loose slot. Own-slot
+#      lineage (legit caller), 0644 slot, PATH-shadowed stat reporting 600 —
+#      mode inspection must come from the trusted PATH and still refuse.
+chmod 644 "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+printf '#!/usr/bin/env bash\necho 600\n' > "$HOSTILE_BIN/stat"
+assert_refused_lineage "F2-R3: hostile stat cannot make a 0644 slot pass as 600 (own-slot path)" \
+  svc-fixture slot-permission-violation \
+  MOSAIC_AGENT_NAME=svc-fixture MOSAIC_GIT_IDENTITY=svc-fixture PATH="$HOSTILE_BIN:$PATH"
+chmod 600 "$BRAIN_DIR/fleet/agents/svc-fixture/secrets/gitea-mosaicstack-svc-fixture.token"
+
+# 11m. rev-code-02 R3 probe 1 through the PRODUCTION ENTRYPOINT: BASH_ENV
+#      defines unset()/exit() no-ops (defeating in-bash scrub/termination).
+#      The python wrapper never passes BASH_ENV across the boundary, so the
+#      implementation cannot be shaped and the dual override still refuses.
+INJ_P1="$WORK_DIR/inj-probe1.sh"
+cat > "$INJ_P1" <<'P1'
+unset() { return 0; }
+exit() { return 0; }
+read() { builtin read -r _x || return 0; printf 'MOSAIC_AGENT_NAME=seatG\n'; return 0; }
+P1
+assert_refused_lineage "F1-R4 probe1: BASH_ENV unset/exit no-ops cannot shape the helper (wrapper boundary)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG BASH_ENV="$INJ_P1"
+
+# 11n. rev-code-02 R3 probe 2 through the PRODUCTION ENTRYPOINT: declare()
+#      hides imported functions, unsets the marker, printf() forges the
+#      ancestry. Dropped at the wrapper boundary; refusal holds.
+INJ_P2="$WORK_DIR/inj-probe2.sh"
+cat > "$INJ_P2" <<'P2'
+declare() { return 0; }
+printf() { builtin printf '%s' "MOSAIC_AGENT_NAME=seatG"; return 0; }
+read() { builtin read -r _x || return 0; printf 'MOSAIC_AGENT_NAME=seatG\n'; return 0; }
+P2
+assert_refused_lineage "F1-R4 probe2: declare-hide + printf-forge cannot shape the helper (wrapper boundary)" \
+  seatE caller-identity-spoof-refused \
+  MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG BASH_ENV="$INJ_P2"
+
+# 11o. RED CONTROL for the wrapper boundary (enforcement-removal): invoke the
+#      IMPLEMENTATION directly, bypassing the wrapper, with the PROBE-1 shape
+#      (unset/exit no-ops) and a forged clean marker — exactly the falsified
+#      in-bash world the reviewer measured: the refusal prints, exit is
+#      no-oped, execution continues, and the forged ancestry SERVES seatG.
+#      The wrapper boundary is the enforcement; this arm proves it bites.
+set +e
+bypass_out=$(cd "$REPO_DIR" && printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+  env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$SPOOL_DIR" \
+    MOSAIC_BRAIN_HOME="$BRAIN_DIR" _MOSAIC_HELPER_CLEAN=1 BASH_ENV="$INJ_P1" \
+    MOSAIC_AGENT_NAME=seatG MOSAIC_GIT_IDENTITY=seatG \
+    bash "$IMPL" get 2>/dev/null)
+set -e
+if [[ "$(echo "$bypass_out" | grep -c '^password=')" -lt 1 ]]; then
+  echo "FAIL: wrapper red control — direct shaped .impl should have served (wrapper is the enforcement), got: $bypass_out" >&2
+  fail=1
+else
+  echo "ok: red control — wrapper bypassed + probe1 shape serves (the wrapper boundary is the enforcement)"
+fi
+
+# 11p. Direct .impl invocation WITHOUT the clean marker: refused by the
+#      implementation's own entrypoint assert.
+set +e
+direct_out=$(cd "$REPO_DIR" && printf 'host=git.mosaicstack.dev\nusername=probe\n\n' | \
+  env -i HOME="$FAKE_HOME" PATH="$PATH" MOSAIC_CREDENTIAL_SPOOL="$SPOOL_DIR" \
+    MOSAIC_BRAIN_HOME="$BRAIN_DIR" MOSAIC_GIT_IDENTITY=seatE \
+    bash "$IMPL" get 2>"$WORK_DIR/stderr-direct.tmp")
+direct_rc=$?
+set -e
+if [[ "$direct_rc" -eq 0 || -n "$direct_out" ]]; then
+  echo "FAIL: direct .impl without marker must refuse (got rc=$direct_rc out='$direct_out')" >&2
+  fail=1
+elif ! grep -q 'direct-entrypoint-refused' "$WORK_DIR/stderr-direct.tmp"; then
+  echo "FAIL: direct .impl refusal lacks direct-entrypoint-refused" >&2
+  fail=1
+fi
+
 if [[ "$fail" -eq 0 ]]; then
   echo "git-credential-mosaic identity resolution regression passed"
 fi

scripts/verify-dogfood-compose.sh

@@ -0,0 +1,176 @@
+#!/usr/bin/env bash
+# Hermetic structural check for the explicit dogfood Compose overlay.
+set -euo pipefail
+
+repo_root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+tmp=$(mktemp -d)
+trap 'rm -rf "$tmp"' EXIT
+mkdir -p "$tmp/worktree" "$tmp/common.git" "$tmp/seat/secrets"
+
+base_config_json=$(
+  cd "$repo_root"
+  BETTER_AUTH_SECRET=test-only-not-a-credential \
+    docker compose --profile stack config --format json
+)
+
+BASE_CONFIG_JSON="$base_config_json" python3 <<'PY'
+import json
+import os
+
+config = json.loads(os.environ["BASE_CONFIG_JSON"])
+gateway = config["services"]["gateway"]
+env = gateway["environment"]
+for key in (
+    "MOSAIC_AGENT_NAME",
+    "MOSAIC_GIT_IDENTITY",
+    "MOSAIC_BRAIN_HOME",
+    "AGENT_FILE_SANDBOX_DIR",
+    "AGENT_USER_TOOLS",
+    "AGENT_SHELL_ENABLED",
+    "AGENT_DELIVERY_ENABLED",
+    "MOSAIC_GIT_TOOLS_DIR",
+    "MOSAIC_INTEGRATION_TRUNK",
+):
+    assert key not in env, f"base compose unexpectedly sets dogfood variable {key}"
+
+targets = {mount["target"] for mount in gateway["volumes"]}
+assert "/workspace/stack" not in targets
+assert not any(target.startswith("/opt/mosaic/brain/") for target in targets)
+PY
+
+config_json=$(
+  cd "$repo_root"
+  BETTER_AUTH_SECRET=test-only-not-a-credential \
+  MOSAIC_DOGFOOD_WORKTREE="$tmp/worktree" \
+  MOSAIC_DOGFOOD_COMMON_GIT_DIR="$tmp/common.git" \
+  MOSAIC_DOGFOOD_SEAT_HOME="$tmp/seat" \
+    docker compose \
+      -f docker-compose.yml \
+      -f docker-compose.dogfood.yml \
+      --profile stack \
+      config --format json
+)
+
+CONFIG_JSON="$config_json" EXPECT_WORKTREE="$tmp/worktree" EXPECT_COMMON_GIT="$tmp/common.git" EXPECT_SEAT="$tmp/seat" python3 <<'PY'
+import json
+import os
+
+config = json.loads(os.environ["CONFIG_JSON"])
+gateway = config["services"]["gateway"]
+assert gateway.get("init") is True, "gateway must run below an init process for R4 lineage"
+env = gateway["environment"]
+
+expected_env = {
+    "MOSAIC_AGENT_NAME": "stack-dogfood",
+    "MOSAIC_GIT_IDENTITY": "stack-dogfood",
+    "MOSAIC_BRAIN_HOME": "/opt/mosaic/brain",
+    "AGENT_FILE_SANDBOX_DIR": "/workspace/stack",
+    "AGENT_SHELL_ENABLED": "false",
+    "AGENT_DELIVERY_ENABLED": "true",
+    "MOSAIC_GIT_TOOLS_DIR": "/opt/mosaic/tools/git",
+    "MOSAIC_INTEGRATION_TRUNK": "next",
+}
+for key, value in expected_env.items():
+    assert env.get(key) == value, f"{key}: expected {value!r}, got {env.get(key)!r}"
+
+allowed = set(env["AGENT_USER_TOOLS"].split(","))
+assert allowed == {
+    "fs_read_file",
+    "fs_write_file",
+    "fs_list_directory",
+    "fs_edit_file",
+    "git_status",
+    "git_log",
+    "git_diff",
+    "git_publish_branch",
+    "git_open_pull_request",
+}, f"unexpected dogfood tool set: {sorted(allowed)}"
+assert "shell_exec" not in allowed
+
+mounts = {mount["target"]: mount for mount in gateway["volumes"]}
+worktree = mounts["/workspace/stack"]
+assert worktree["type"] == "bind"
+assert worktree["source"] == os.environ["EXPECT_WORKTREE"]
+assert not worktree.get("read_only", False), "dogfood worktree must be writable"
+
+common_git = mounts[os.environ["EXPECT_COMMON_GIT"]]
+assert common_git["type"] == "bind"
+assert common_git["source"] == os.environ["EXPECT_COMMON_GIT"]
+assert not common_git.get("read_only", False), "common Git directory must accept branch updates"
+
+seat = mounts["/opt/mosaic/brain/fleet/agents/stack-dogfood"]
+assert seat["type"] == "bind"
+assert seat["source"] == os.environ["EXPECT_SEAT"]
+assert seat.get("read_only") is True, "seat credential slot must be read-only"
+
+other_seat_mounts = [
+    target
+    for target in mounts
+    if target.startswith("/opt/mosaic/brain/fleet/agents/")
+    and target != "/opt/mosaic/brain/fleet/agents/stack-dogfood"
+]
+assert other_seat_mounts == [], f"other seat mounts leaked: {other_seat_mounts}"
+PY
+
+# Each required path must fail closed rather than falling back to the current checkout.
+expect_missing_path() {
+  local missing=$1 output rc
+  set +e
+  case "$missing" in
+    MOSAIC_DOGFOOD_WORKTREE)
+      output=$(
+        cd "$repo_root"
+        env -u MOSAIC_DOGFOOD_WORKTREE \
+          BETTER_AUTH_SECRET=test-only-not-a-credential \
+          MOSAIC_DOGFOOD_COMMON_GIT_DIR="$tmp/common.git" \
+          MOSAIC_DOGFOOD_SEAT_HOME="$tmp/seat" \
+          docker compose -f docker-compose.yml -f docker-compose.dogfood.yml \
+            --profile stack config 2>&1
+      )
+      rc=$?
+      ;;
+    MOSAIC_DOGFOOD_COMMON_GIT_DIR)
+      output=$(
+        cd "$repo_root"
+        env -u MOSAIC_DOGFOOD_COMMON_GIT_DIR \
+          BETTER_AUTH_SECRET=test-only-not-a-credential \
+          MOSAIC_DOGFOOD_WORKTREE="$tmp/worktree" \
+          MOSAIC_DOGFOOD_SEAT_HOME="$tmp/seat" \
+          docker compose -f docker-compose.yml -f docker-compose.dogfood.yml \
+            --profile stack config 2>&1
+      )
+      rc=$?
+      ;;
+    MOSAIC_DOGFOOD_SEAT_HOME)
+      output=$(
+        cd "$repo_root"
+        env -u MOSAIC_DOGFOOD_SEAT_HOME \
+          BETTER_AUTH_SECRET=test-only-not-a-credential \
+          MOSAIC_DOGFOOD_WORKTREE="$tmp/worktree" \
+          MOSAIC_DOGFOOD_COMMON_GIT_DIR="$tmp/common.git" \
+          docker compose -f docker-compose.yml -f docker-compose.dogfood.yml \
+            --profile stack config 2>&1
+      )
+      rc=$?
+      ;;
+    *)
+      echo "FAIL: test requested unknown path variable $missing" >&2
+      exit 1
+      ;;
+  esac
+  set -e
+  if [[ $rc -eq 0 ]]; then
+    echo "FAIL: dogfood compose accepted missing $missing" >&2
+    exit 1
+  fi
+  if [[ "$output" != *"$missing"* ]]; then
+    echo "FAIL: missing-path failure did not name $missing" >&2
+    exit 1
+  fi
+}
+
+expect_missing_path MOSAIC_DOGFOOD_WORKTREE
+expect_missing_path MOSAIC_DOGFOOD_COMMON_GIT_DIR
+expect_missing_path MOSAIC_DOGFOOD_SEAT_HOME
+
+printf 'dogfood compose verification passed\n'