docs: finalize ri-4-001 scratchpad with verification evidence (#1275)

- import paths: created/draft, typed refusal creates nothing, conflict
  refusal leaves bytes untouched, --accept-successor persists v+1
- export writes the labeled generated view; authority unchanged
- mission --plan persists linkage readable by a fresh service instance;
  mission path and prdy path share the docs/prdy store with stable
  ids/versions

apps/web/src/components/freshness/freshness-notices.tsx

@@ -1,110 +0,0 @@
-'use client';
-
-import type { ReactElement } from 'react';
-import { formatAge, type FreshnessLabel } from '@/lib/freshness/model';
-
-/**
- * Rendering rules for non-current freshness states (RI-5-001).
- *
- * - `unavailable` renders an explicit failure panel — never an empty
- *   healthy collection.
- * - `stale` may render last-known data, but only under a visible label
- *   carrying source identity, snapshot version, and age.
- * - `partial` renders the verified parts plus an explicit list of what is
- *   missing.
- */
-
-interface RetryableNoticeProps {
-  readonly onRetry?: () => void;
-  readonly retryLabel?: string;
-}
-
-function RetryButton({ onRetry, retryLabel }: RetryableNoticeProps): ReactElement | null {
-  if (!onRetry) return null;
-  return (
-    <button
-      type="button"
-      onClick={onRetry}
-      className="mt-2 rounded-lg border border-surface-border px-3 py-1.5 text-xs transition-colors hover:border-gray-500"
-    >
-      {retryLabel ?? 'Retry'}
-    </button>
-  );
-}
-
-export interface UnavailableDataNoticeProps extends RetryableNoticeProps {
-  /** What is unavailable, e.g. "Tasks". */
-  readonly title: string;
-  /** Optional underlying failure detail (network message, invalidation reason). */
-  readonly detail?: string | null;
-}
-
-/** Explicit `unavailable` state. Never renders as an empty healthy collection. */
-export function UnavailableDataNotice({
-  title,
-  detail,
-  onRetry,
-  retryLabel,
-}: UnavailableDataNoticeProps): ReactElement {
-  return (
-    <div role="alert" className="rounded-lg border border-error/40 px-4 py-3 text-sm">
-      <p className="font-medium text-text-primary">{title} are unavailable</p>
-      <p className="mt-1 text-text-muted">
-        This is not an empty result — the data could not be verified from the gateway.
-        {detail ? ` ${detail}` : ''}
-      </p>
-      <RetryButton onRetry={onRetry} retryLabel={retryLabel} />
-    </div>
-  );
-}
-
-export interface StaleDataNoticeProps extends RetryableNoticeProps {
-  /** Provenance of the last-known snapshot being displayed. */
-  readonly label: FreshnessLabel;
-}
-
-/**
- * Situational-awareness banner for `stale` data: last-known data may render,
- * but visibly labeled with source identity, snapshot version, and age.
- */
-export function StaleDataNotice({
-  label,
-  onRetry,
-  retryLabel,
-}: StaleDataNoticeProps): ReactElement {
-  return (
-    <div role="status" className="rounded-lg border border-warning/40 px-4 py-3 text-sm">
-      <p className="font-medium text-warning">Showing last-known data — it may be out of date</p>
-      <p className="mt-1 text-xs text-text-muted">
-        Source {label.source} · snapshot v{label.version} · fetched{' '}
-        {formatAge(label.fetchedAt, Date.now())}. Verdicts derived from this data are unknown and
-        changes are disabled until it is revalidated.
-      </p>
-      <RetryButton onRetry={onRetry} retryLabel={retryLabel ?? 'Revalidate'} />
-    </div>
-  );
-}
-
-export interface PartialDataNoticeProps extends RetryableNoticeProps {
-  /** Display names of the sections whose collections are unavailable. */
-  readonly missing: readonly string[];
-}
-
-/** `partial` surface banner: verified parts render, missing parts are explicit. */
-export function PartialDataNotice({
-  missing,
-  onRetry,
-  retryLabel,
-}: PartialDataNoticeProps): ReactElement {
-  return (
-    <div role="status" className="rounded-lg border border-warning/40 px-4 py-3 text-sm">
-      <p className="font-medium text-warning">Some data could not be loaded</p>
-      <p className="mt-1 text-xs text-text-muted">
-        {missing.join(', ')} {missing.length === 1 ? 'is' : 'are'} unavailable — sections below show
-        an explicit unavailable state instead of an empty list. Derived verdicts remain unknown
-        until every collection is revalidated.
-      </p>
-      <RetryButton onRetry={onRetry} retryLabel={retryLabel ?? 'Revalidate'} />
-    </div>
-  );
-}

apps/web/src/lib/freshness/model.spec.ts

@@ -1,324 +0,0 @@
-import { describe, expect, it } from 'vitest';
-import type { Task } from '@/lib/types';
-import {
-  acceptSnapshot,
-  assertMutable,
-  canMutate,
-  combineFreshness,
-  computeDigest,
-  computeFreshness,
-  DEFAULT_FRESHNESS_POLICY,
-  formatAge,
-  type FreshSnapshot,
-  invalidationReasonLabels,
-  StaleMutationError,
-  UNKNOWN_VERDICT,
-  verdictValue,
-} from './model';
-import { validateProjectCollection, validateTaskCollection } from './validators';
-
-const NOW = 1_800_000_000_000;
-
-const policy = { ...DEFAULT_FRESHNESS_POLICY, staleAfterMs: 60_000 };
-
-const taskPayload: Task[] = [
-  {
-    id: 'task-1',
-    title: 'T1',
-    description: null,
-    status: 'not-started',
-    priority: 'high',
-    projectId: 'project-1',
-    missionId: null,
-    assignee: null,
-    tags: null,
-    dueDate: null,
-    metadata: null,
-    createdAt: '2026-08-01T00:00:00.000Z',
-    updatedAt: '2026-08-01T00:00:00.000Z',
-  },
-];
-
-function acceptedTaskSnapshot(
-  overrides: Partial<FreshSnapshot<typeof taskPayload>> = {},
-): FreshSnapshot<typeof taskPayload> {
-  const result = acceptSnapshot({
-    value: taskPayload,
-    validate: validateTaskCollection,
-    previous: null,
-    policy,
-    source: 'gateway:/api/tasks',
-    now: NOW,
-  });
-  if (result.outcome !== 'accepted') {
-    throw new Error(`fixture setup failed: ${result.reason}`);
-  }
-  return { ...result.snapshot, ...overrides };
-}
-
-describe('computeFreshness', () => {
-  it('treats a missing snapshot as unavailable, never as an empty healthy collection', () => {
-    expect(computeFreshness({ snapshot: null, policy, now: NOW })).toBe('unavailable');
-  });
-
-  it('returns current for a fresh verified snapshot regardless of data emptiness', () => {
-    const empty = acceptSnapshot({
-      value: [],
-      validate: validateTaskCollection,
-      previous: null,
-      policy,
-      source: 'gateway:/api/tasks',
-      now: NOW,
-    });
-    if (empty.outcome !== 'accepted') throw new Error('expected acceptance');
-    expect(computeFreshness({ snapshot: empty.snapshot, policy, now: NOW })).toBe('current');
-  });
-
-  it('degrades to stale once the snapshot ages past staleAfterMs', () => {
-    const snapshot = acceptedTaskSnapshot();
-    expect(computeFreshness({ snapshot, policy, now: NOW + 60_001 })).toBe('stale');
-    expect(computeFreshness({ snapshot, policy, now: NOW + 59_999 })).toBe('current');
-  });
-
-  it('degrades to stale when the latest revalidation failed', () => {
-    const snapshot = acceptedTaskSnapshot();
-    expect(computeFreshness({ snapshot, policy, now: NOW, degraded: true })).toBe('stale');
-  });
-});
-
-describe('mutation guard', () => {
-  it('permits mutations only on current data', () => {
-    expect(canMutate('current')).toBe(true);
-    for (const state of ['stale', 'partial', 'unknown', 'unavailable'] as const) {
-      expect(canMutate(state)).toBe(false);
-    }
-  });
-
-  it('refuses mutations on non-current data via assertMutable', () => {
-    expect(() => assertMutable('current')).not.toThrow();
-    for (const state of ['stale', 'partial', 'unknown', 'unavailable'] as const) {
-      let thrown: unknown;
-      try {
-        assertMutable(state);
-      } catch (caught) {
-        thrown = caught;
-      }
-      expect(thrown).toBeInstanceOf(StaleMutationError);
-      expect(thrown).toBeInstanceOf(Error);
-      if (thrown instanceof StaleMutationError) {
-        expect(thrown.name).toBe('StaleMutationError');
-        expect(thrown.freshness).toBe(state);
-        expect(thrown.message).toContain(state);
-        expect(thrown.message).toContain('revalidat');
-      }
-    }
-  });
-});
-
-describe('acceptSnapshot', () => {
-  it('accepts a valid payload with provenance', () => {
-    const result = acceptSnapshot({
-      value: taskPayload,
-      validate: validateTaskCollection,
-      previous: null,
-      policy,
-      source: 'gateway:/api/tasks',
-      now: NOW,
-    });
-    expect(result.outcome).toBe('accepted');
-    if (result.outcome !== 'accepted') return;
-    expect(result.snapshot.source).toBe('gateway:/api/tasks');
-    expect(result.snapshot.version).toBe(1);
-    expect(result.snapshot.fetchedAt).toBe(NOW);
-    expect(result.snapshot.data).toEqual(taskPayload);
-  });
-
-  it('invalidates a schema-mismatched payload instead of rendering it', () => {
-    const result = acceptSnapshot({
-      value: { not: 'an array' },
-      validate: validateTaskCollection,
-      previous: acceptedTaskSnapshot(),
-      policy,
-      source: 'gateway:/api/tasks',
-      now: NOW,
-    });
-    expect(result).toEqual({ outcome: 'invalidated', reason: 'schema-mismatch' });
-    expect(invalidationReasonLabels['schema-mismatch']).toContain('schema');
-  });
-
-  it('invalidates cross-workspace payloads', () => {
-    const userOne = acceptSnapshot({
-      value: [
-        {
-          id: 'p1',
-          name: 'P1',
-          description: null,
-          status: 'active',
-          userId: 'user-1',
-          metadata: null,
-          createdAt: '2026-08-01T00:00:00.000Z',
-          updatedAt: '2026-08-01T00:00:00.000Z',
-        },
-      ],
-      validate: validateProjectCollection,
-      previous: null,
-      policy,
-      source: 'gateway:/api/projects',
-      now: NOW,
-    });
-    if (userOne.outcome !== 'accepted') throw new Error('expected acceptance');
-
-    const switched = acceptSnapshot({
-      value: [
-        {
-          id: 'p9',
-          name: 'P9',
-          description: null,
-          status: 'active',
-          userId: 'user-2',
-          metadata: null,
-          createdAt: '2026-08-01T00:00:00.000Z',
-          updatedAt: '2026-08-01T00:00:00.000Z',
-        },
-      ],
-      validate: validateProjectCollection,
-      previous: userOne.snapshot,
-      policy,
-      source: 'gateway:/api/projects',
-      now: NOW,
-    });
-    expect(switched).toEqual({ outcome: 'invalidated', reason: 'cross-workspace' });
-  });
-
-  it('keeps the previous workspace for collections with no intrinsic identity', () => {
-    const userOne = acceptSnapshot({
-      value: [
-        {
-          id: 'p1',
-          name: 'P1',
-          description: null,
-          status: 'active',
-          userId: 'user-1',
-          metadata: null,
-          createdAt: '2026-08-01T00:00:00.000Z',
-          updatedAt: '2026-08-01T00:00:00.000Z',
-        },
-      ],
-      validate: validateProjectCollection,
-      previous: null,
-      policy,
-      source: 'gateway:/api/projects',
-      now: NOW,
-    });
-    if (userOne.outcome !== 'accepted') throw new Error('expected acceptance');
-
-    // Empty list after the user deleted every project: no identity to check,
-    // so the verified scope is retained and the empty state stays healthy.
-    const emptied = acceptSnapshot({
-      value: [],
-      validate: validateProjectCollection,
-      previous: userOne.snapshot,
-      policy,
-      source: 'gateway:/api/projects',
-      now: NOW,
-    });
-    expect(emptied.outcome).toBe('accepted');
-    if (emptied.outcome === 'accepted') {
-      expect(emptied.snapshot.data).toEqual([]);
-      expect(emptied.snapshot.workspace).toBe('user-1');
-    }
-  });
-
-  it('invalidates version regressions', () => {
-    const previous = acceptedTaskSnapshot({ version: 7 });
-    const regressed = acceptSnapshot({
-      value: taskPayload,
-      validate: validateTaskCollection,
-      previous,
-      policy,
-      source: 'gateway:/api/tasks',
-      now: NOW,
-      incomingVersion: 3,
-    });
-    expect(regressed).toEqual({ outcome: 'invalidated', reason: 'version-regression' });
-
-    const newerSchema = acceptedTaskSnapshot({ schemaVersion: 4 });
-    const downgradedClient = acceptSnapshot({
-      value: taskPayload,
-      validate: validateTaskCollection,
-      previous: newerSchema,
-      policy: { ...policy, schemaVersion: 2 },
-      source: 'gateway:/api/tasks',
-      now: NOW,
-    });
-    expect(downgradedClient).toEqual({ outcome: 'invalidated', reason: 'version-regression' });
-  });
-
-  it('increments the version monotonically across accepted snapshots', () => {
-    const first = acceptedTaskSnapshot();
-    const second = acceptSnapshot({
-      value: taskPayload,
-      validate: validateTaskCollection,
-      previous: first,
-      policy,
-      source: 'gateway:/api/tasks',
-      now: NOW,
-    });
-    expect(second.outcome).toBe('accepted');
-    if (second.outcome === 'accepted') {
-      expect(second.snapshot.version).toBe(first.version + 1);
-    }
-  });
-});
-
-describe('combineFreshness', () => {
-  it('gates the surface on the primary collection', () => {
-    expect(combineFreshness('unavailable', ['current'])).toBe('unavailable');
-    expect(combineFreshness('unknown', ['current'])).toBe('unknown');
-    expect(combineFreshness('current', [])).toBe('current');
-  });
-
-  it('degrades to partial when a secondary is unavailable', () => {
-    expect(combineFreshness('current', ['current', 'unavailable'])).toBe('partial');
-  });
-
-  it('degrades to unknown while a secondary is still loading', () => {
-    expect(combineFreshness('current', ['unknown'])).toBe('unknown');
-  });
-
-  it('degrades to stale when any collection is stale', () => {
-    expect(combineFreshness('current', ['stale'])).toBe('stale');
-    expect(combineFreshness('stale', ['current'])).toBe('stale');
-  });
-
-  it('propagates partial secondaries', () => {
-    expect(combineFreshness('current', ['partial'])).toBe('partial');
-  });
-});
-
-describe('computeDigest', () => {
-  it('is stable across key order and changes with data', () => {
-    const a = computeDigest({ x: 1, y: [1, 2] });
-    const b = computeDigest({ y: [1, 2], x: 1 });
-    expect(a).toBe(b);
-    expect(computeDigest({ x: 1, y: [1, 3] })).not.toBe(a);
-  });
-});
-
-describe('verdictValue', () => {
-  it('returns the value only for verified inputs', () => {
-    expect(verdictValue(true, '5')).toBe('5');
-    expect(verdictValue(false, '5')).toBe(UNKNOWN_VERDICT);
-    expect(verdictValue(false, '5')).not.toBe('5');
-  });
-});
-
-describe('formatAge', () => {
-  it('labels age in human terms', () => {
-    expect(formatAge(NOW, NOW)).toBe('just now');
-    expect(formatAge(NOW, NOW + 15_000)).toBe('under a minute ago');
-    expect(formatAge(NOW, NOW + 120_000)).toBe('2m ago');
-    expect(formatAge(NOW, NOW + 3 * 3_600_000)).toBe('3h ago');
-    expect(formatAge(NOW, NOW + 2 * 86_400_000)).toBe('2d ago');
-  });
-});

apps/web/src/lib/freshness/model.ts

@@ -1,261 +0,0 @@
-/**
- * Typed freshness model for gateway-fetched collections (RI-5-001).
- *
- * A failed or stale fetch must never be indistinguishable from an empty
- * healthy collection. Every fetched surface carries an explicit freshness
- * state, a verified snapshot identity (source, workspace, version, age), and
- * a mutation guard that refuses state-changing operations unless the data is
- * verified current.
- */
-
-/** Freshness states for fetched data. Never inferred from emptiness. */
-export type FreshnessState = 'current' | 'stale' | 'partial' | 'unknown' | 'unavailable';
-
-/**
- * Reasons a snapshot is invalidated. An invalidated snapshot is treated as
- * unavailable and is never rendered as current.
- */
-export type InvalidationReason =
-  | 'cache-corruption'
-  | 'cross-workspace'
-  | 'schema-mismatch'
-  | 'version-regression';
-
-/** Human-readable labels for invalidation reasons (UI + error messages). */
-export const invalidationReasonLabels: Record<InvalidationReason, string> = {
-  'cache-corruption': 'cached snapshot failed integrity checks',
-  'cross-workspace': 'data belongs to a different workspace',
-  'schema-mismatch': 'response did not match the expected schema',
-  'version-regression': 'snapshot version regressed below the accepted version',
-};
-
-/** A verified snapshot of fetched data with full provenance. */
-export interface FreshSnapshot<T> {
-  readonly data: T;
-  /** Source identity of the fetch, e.g. `gateway:/api/tasks`. */
-  readonly source: string;
-  /** Workspace scope the data belongs to. */
-  readonly workspace: string;
-  /** Monotonic snapshot sequence number for this surface. */
-  readonly version: number;
-  /** Schema version of the validator that accepted this snapshot. */
-  readonly schemaVersion: number;
-  /** Epoch ms at which the data was verified. */
-  readonly fetchedAt: number;
-  /** Integrity digest of `data`, used to detect cache corruption. */
-  readonly digest: string;
-}
-
-/** Provenance label rendered next to last-known data. */
-export interface FreshnessLabel {
-  readonly source: string;
-  readonly version: number;
-  readonly fetchedAt: number;
-}
-
-/** Policy governing freshness for a surface. */
-export interface FreshnessPolicy {
-  /** Active workspace scope. Snapshots from other scopes are invalidated. */
-  readonly workspace: string;
-  /** Schema version of the current validator. */
-  readonly schemaVersion: number;
-  /** Age after which a verified snapshot degrades from current to stale. */
-  readonly staleAfterMs: number;
-}
-
-export const DEFAULT_FRESHNESS_POLICY: FreshnessPolicy = {
-  workspace: 'default',
-  schemaVersion: 1,
-  staleAfterMs: 60_000,
-};
-
-/** Payload returned by a successful schema validation. */
-export interface FreshPayload<T> {
-  readonly data: T;
-  /**
-   * Workspace identity extracted from the payload itself when the collection
-   * carries one (e.g. a uniform `userId` on projects). `null` when the
-   * collection has no intrinsic workspace identity.
-   */
-  readonly workspace: string | null;
-}
-
-/** Error thrown when a mutation is attempted on non-current data. */
-export class StaleMutationError extends Error {
-  readonly freshness: FreshnessState;
-
-  constructor(freshness: FreshnessState) {
-    super(`Refused mutation on ${freshness} data: revalidation is required before mutating.`);
-    this.name = 'StaleMutationError';
-    this.freshness = freshness;
-  }
-}
-
-/** Stable JSON digest used for snapshot integrity checks. */
-export function computeDigest(value: unknown): string {
-  // FNV-1a 32-bit over the stable JSON serialization. This is an integrity
-  // check against corruption, not a cryptographic guarantee.
-  let hash = 0x811c9dc5;
-  for (const byte of stableStringify(value)) {
-    hash ^= byte.charCodeAt(0);
-    hash = Math.imul(hash, 0x01000193) >>> 0;
-  }
-  return hash.toString(16).padStart(8, '0');
-}
-
-function stableStringify(value: unknown): string {
-  return serialize(value);
-}
-
-function serialize(value: unknown): string {
-  if (value === null || typeof value !== 'object') return JSON.stringify(value) ?? 'null';
-  if (Array.isArray(value)) return `[${value.map(serialize).join(',')}]`;
-  const entries = Object.entries(value as Record<string, unknown>)
-    .filter(([, item]) => item !== undefined)
-    .sort(([left], [right]) => (left < right ? -1 : left > right ? 1 : 0))
-    .map(([key, item]) => `${JSON.stringify(key)}:${serialize(item)}`);
-  return `{${entries.join(',')}}`;
-}
-
-export type AcceptSnapshotResult<T> =
-  | { readonly outcome: 'accepted'; readonly snapshot: FreshSnapshot<T> }
-  | { readonly outcome: 'invalidated'; readonly reason: InvalidationReason };
-
-export interface AcceptSnapshotOptions<T> {
-  /** Raw fetched value (untrusted JSON). */
-  readonly value: unknown;
-  /** Schema validator; returns `null` when the value does not match. */
-  readonly validate: (value: unknown) => FreshPayload<T> | null;
-  /** Previously accepted snapshot for this surface, if any. */
-  readonly previous: FreshSnapshot<T> | null;
-  readonly policy: FreshnessPolicy;
-  readonly source: string;
-  /**
-   * Version carried by the incoming payload when the transport exposes one.
-   * Must not regress below the accepted snapshot's version.
-   */
-  readonly incomingVersion?: number;
-  readonly now: number;
-}
-
-/**
- * Validate and accept a fetched value as a snapshot, or invalidate it.
- *
- * Invalidation rules (each treated as unavailable, never rendered current):
- * - schema mismatch: the payload fails validation
- * - cross-workspace: the payload's workspace differs from the verified one
- * - version regression: payload/schema version is below the accepted one
- */
-export function acceptSnapshot<T>(options: AcceptSnapshotOptions<T>): AcceptSnapshotResult<T> {
-  const payload = options.validate(options.value);
-  if (payload === null) {
-    return { outcome: 'invalidated', reason: 'schema-mismatch' };
-  }
-
-  // Workspace identity: the payload's own scope wins; a collection with no
-  // intrinsic identity (e.g. an empty list after every project was deleted)
-  // keeps the previously verified scope rather than resetting to the policy
-  // default, so a legitimately empty response is not mistaken for a scope
-  // change.
-  const workspace = payload.workspace ?? options.previous?.workspace ?? options.policy.workspace;
-  if (options.previous !== null && options.previous.workspace !== workspace) {
-    return { outcome: 'invalidated', reason: 'cross-workspace' };
-  }
-  if (options.previous !== null && options.policy.schemaVersion < options.previous.schemaVersion) {
-    return { outcome: 'invalidated', reason: 'version-regression' };
-  }
-  if (
-    options.incomingVersion !== undefined &&
-    options.previous !== null &&
-    options.incomingVersion < options.previous.version
-  ) {
-    return { outcome: 'invalidated', reason: 'version-regression' };
-  }
-
-  const snapshot: FreshSnapshot<T> = {
-    data: payload.data,
-    source: options.source,
-    workspace,
-    version: options.incomingVersion ?? (options.previous?.version ?? 0) + 1,
-    schemaVersion: options.policy.schemaVersion,
-    fetchedAt: options.now,
-    digest: computeDigest(payload.data),
-  };
-  return { outcome: 'accepted', snapshot };
-}
-
-export interface ComputeFreshnessOptions {
-  readonly snapshot: FreshSnapshot<unknown> | null;
-  readonly policy: FreshnessPolicy;
-  readonly now: number;
-  /**
-   * True when the snapshot cannot be trusted as current regardless of age:
-   * the latest revalidation failed, or the snapshot was restored from cache
-   * and has not been verified by a fetch in this session.
-   */
-  readonly degraded?: boolean;
-}
-
-/**
- * Compute the freshness state of a snapshot. A missing snapshot is
- * `unavailable` (never "empty and healthy"); a degraded or aged snapshot is
- * `stale` (situational awareness only).
- */
-export function computeFreshness(options: ComputeFreshnessOptions): FreshnessState {
-  const { snapshot, policy, now, degraded = false } = options;
-  if (snapshot === null) return 'unavailable';
-  if (degraded) return 'stale';
-  if (now - snapshot.fetchedAt > policy.staleAfterMs) return 'stale';
-  return 'current';
-}
-
-/** Only verified-current data may back a state-changing action. */
-export function canMutate(state: FreshnessState): boolean {
-  return state === 'current';
-}
-
-/** Defense in depth: reject the mutation call itself on non-current data. */
-export function assertMutable(state: FreshnessState): void {
-  if (!canMutate(state)) {
-    throw new StaleMutationError(state);
-  }
-}
-
-/**
- * Combine freshness across a multi-collection surface (primary + secondaries).
- * The primary collection gates the surface: unknown while it loads,
- * unavailable when it fails. Missing secondaries degrade the surface to
- * `partial`; aged collections degrade it to `stale`.
- */
-export function combineFreshness(
-  primary: FreshnessState,
-  secondaries: readonly FreshnessState[],
-): FreshnessState {
-  if (primary === 'unavailable') return 'unavailable';
-  if (primary === 'unknown') return 'unknown';
-  if (secondaries.includes('unavailable')) return 'partial';
-  if (secondaries.includes('unknown')) return 'unknown';
-  if (secondaries.includes('stale') || primary === 'stale') return 'stale';
-  if (secondaries.includes('partial')) return 'partial';
-  return 'current';
-}
-
-/** Render-safe age label for snapshot provenance. */
-export function formatAge(fetchedAt: number, now: number): string {
-  const ageMs = Math.max(0, now - fetchedAt);
-  if (ageMs < 10_000) return 'just now';
-  const minutes = Math.floor(ageMs / 60_000);
-  if (minutes < 1) return 'under a minute ago';
-  if (minutes < 60) return `${minutes}m ago`;
-  const hours = Math.floor(minutes / 60);
-  if (hours < 24) return `${hours}h ago`;
-  const days = Math.floor(hours / 24);
-  return `${days}d ago`;
-}
-
-/** Derived verdict placeholder for non-current inputs — never a green value. */
-export const UNKNOWN_VERDICT = '?';
-
-export function verdictValue(verified: boolean, value: string): string {
-  return verified ? value : UNKNOWN_VERDICT;
-}

apps/web/src/lib/freshness/snapshot-cache.spec.ts

@@ -1,197 +0,0 @@
-import { afterEach, beforeEach, describe, expect, it } from 'vitest';
-import { acceptSnapshot, DEFAULT_FRESHNESS_POLICY } from './model';
-import { clearSnapshotCache, readSnapshotCache, writeSnapshotCache } from './snapshot-cache';
-import { validateProjectCollection, validateTaskCollection } from './validators';
-import { projectFixtures, taskFixtures } from '@/spa/pages/page-fixtures';
-import type { Project, Task } from '@/lib/types';
-
-const KEY = 'test:tasks';
-const NOW = 1_800_000_000_000;
-const policy = { ...DEFAULT_FRESHNESS_POLICY, staleAfterMs: 60_000 };
-
-function storedTaskSnapshot() {
-  const result = acceptSnapshot({
-    value: taskFixtures,
-    validate: validateTaskCollection,
-    previous: null,
-    policy,
-    source: 'gateway:/api/tasks',
-    now: NOW,
-  });
-  if (result.outcome !== 'accepted') throw new Error('fixture setup failed');
-  return result.snapshot;
-}
-
-function storedProjectSnapshot() {
-  const result = acceptSnapshot({
-    value: projectFixtures,
-    validate: validateProjectCollection,
-    previous: null,
-    policy,
-    source: 'gateway:/api/projects',
-    now: NOW,
-  });
-  if (result.outcome !== 'accepted') throw new Error('fixture setup failed');
-  return result.snapshot;
-}
-
-function readTasks() {
-  return readSnapshotCache({
-    key: KEY,
-    workspace: policy.workspace,
-    policy,
-    validate: validateTaskCollection,
-  });
-}
-
-/** Write an arbitrary value directly at the raw cache slot. */
-function writeRaw(key: string, value: unknown): void {
-  sessionStorage.setItem(`mosaic:freshness:v1:${key}`, JSON.stringify(value));
-}
-
-/** Parse and re-write the stored entry (for tampering with internals). */
-function tamperStored<T>(key: string, mutate: (stored: T) => void): void {
-  const parsed = JSON.parse(sessionStorage.getItem(`mosaic:freshness:v1:${key}`) ?? '{}') as T;
-  mutate(parsed);
-  writeRaw(key, parsed);
-}
-
-beforeEach(() => {
-  sessionStorage.clear();
-});
-
-afterEach(() => {
-  sessionStorage.clear();
-});
-
-describe('readSnapshotCache', () => {
-  it('misses when nothing is stored', () => {
-    expect(readTasks()).toEqual({ outcome: 'miss' });
-  });
-
-  it('hits for a well-formed entry and preserves provenance', () => {
-    const snapshot = storedTaskSnapshot();
-    writeSnapshotCache(KEY, snapshot);
-
-    const result = readTasks();
-    expect(result.outcome).toBe('hit');
-    if (result.outcome === 'hit') {
-      expect(result.snapshot.data).toEqual(taskFixtures);
-      expect(result.snapshot.source).toBe('gateway:/api/tasks');
-      expect(result.snapshot.version).toBe(snapshot.version);
-      expect(result.snapshot.fetchedAt).toBe(snapshot.fetchedAt);
-      expect(result.snapshot.workspace).toBe(snapshot.workspace);
-    }
-  });
-
-  it('invalidates unparsable entries as cache corruption', () => {
-    sessionStorage.setItem(`mosaic:freshness:v1:${KEY}`, '{not json');
-    expect(readTasks()).toEqual({ outcome: 'invalidated', reason: 'cache-corruption' });
-  });
-
-  it('invalidates structurally wrong entries as cache corruption', () => {
-    const malformed: unknown[] = [
-      'nested but not a snapshot',
-      { data: taskFixtures }, // missing provenance fields
-      {
-        data: taskFixtures,
-        source: 1,
-        workspace: 'w',
-        version: 1,
-        schemaVersion: 1,
-        fetchedAt: 1,
-        digest: 'x',
-      },
-      null,
-      17,
-    ];
-    for (const entry of malformed) {
-      writeRaw(KEY, entry);
-      expect(readTasks()).toEqual({ outcome: 'invalidated', reason: 'cache-corruption' });
-    }
-  });
-
-  it('invalidates digest mismatches as cache corruption (tampered data)', () => {
-    writeSnapshotCache(KEY, storedTaskSnapshot());
-    tamperStored<{ data: Task[] }>(KEY, (stored) => {
-      stored.data = [...stored.data, { ...stored.data[0]!, id: 'injected-task' }];
-    });
-    expect(readTasks()).toEqual({ outcome: 'invalidated', reason: 'cache-corruption' });
-  });
-
-  it('invalidates entries scoped to another workspace', () => {
-    const snapshot = storedTaskSnapshot();
-    writeSnapshotCache(KEY, { ...snapshot, workspace: 'someone-else' });
-    expect(readTasks()).toEqual({ outcome: 'invalidated', reason: 'cross-workspace' });
-  });
-
-  it('invalidates entries written by a newer schema as a version regression', () => {
-    const snapshot = storedTaskSnapshot();
-    writeSnapshotCache(KEY, { ...snapshot, schemaVersion: policy.schemaVersion + 1 });
-    expect(readTasks()).toEqual({ outcome: 'invalidated', reason: 'version-regression' });
-  });
-
-  it('invalidates entries whose data no longer validates (schema mismatch)', () => {
-    writeSnapshotCache(KEY, storedTaskSnapshot());
-    tamperStored<{ data: unknown }>(KEY, (stored) => {
-      stored.data = { malformed: true };
-    });
-    expect(readTasks()).toEqual({ outcome: 'invalidated', reason: 'schema-mismatch' });
-  });
-
-  it('never reports a corrupted raw entry as a hit (negative control)', () => {
-    for (const raw of ['{oops', 'null', '"string"', '[]', '12']) {
-      sessionStorage.setItem(`mosaic:freshness:v1:${KEY}`, raw);
-      const result = readTasks();
-      expect(result.outcome).not.toBe('hit');
-      expect(result.outcome).toBe('invalidated');
-    }
-  });
-
-  it('scopes project collections by their workspace identity', () => {
-    const snapshot = storedProjectSnapshot();
-    writeSnapshotCache('test:projects', snapshot);
-
-    const sameScope = readSnapshotCache({
-      key: 'test:projects',
-      workspace: 'user-1',
-      policy,
-      validate: validateProjectCollection,
-    });
-    expect(sameScope.outcome).toBe('hit');
-
-    const foreignScope = readSnapshotCache({
-      key: 'test:projects',
-      workspace: 'user-2',
-      policy,
-      validate: validateProjectCollection,
-    });
-    expect(foreignScope).toEqual({ outcome: 'invalidated', reason: 'cross-workspace' });
-  });
-});
-
-describe('writeSnapshotCache round-trip', () => {
-  it('round-trips an accepted project snapshot', () => {
-    const snapshot = storedProjectSnapshot();
-    writeSnapshotCache('test:projects', snapshot);
-    const result = readSnapshotCache({
-      key: 'test:projects',
-      workspace: snapshot.workspace,
-      policy,
-      validate: validateProjectCollection,
-    });
-    expect(result.outcome).toBe('hit');
-    if (result.outcome === 'hit') {
-      expect(result.snapshot.data).toEqual(projectFixtures as Project[]);
-    }
-  });
-});
-
-describe('clearSnapshotCache', () => {
-  it('drops the entry so the next read misses', () => {
-    writeSnapshotCache(KEY, storedTaskSnapshot());
-    expect(readTasks().outcome).toBe('hit');
-    clearSnapshotCache(KEY);
-    expect(readTasks()).toEqual({ outcome: 'miss' });
-  });
-});

apps/web/src/lib/freshness/snapshot-cache.ts

@@ -1,154 +0,0 @@
-import {
-  computeDigest,
-  type FreshPayload,
-  type FreshSnapshot,
-  type FreshnessPolicy,
-  type InvalidationReason,
-} from './model';
-
-/**
- * Session-scoped last-known snapshot cache (RI-5-001).
- *
- * Restored snapshots are situational awareness only: they surface as `stale`
- * until a fetch re-verifies them. A cache entry that is corrupted, belongs to
- * another workspace, was written by a newer schema, or no longer validates is
- * invalidated (treated as unavailable, never rendered as current).
- */
-
-const CACHE_PREFIX = 'mosaic:freshness:v1';
-
-interface StoredSnapshot {
-  data: unknown;
-  source: string;
-  workspace: string;
-  version: number;
-  schemaVersion: number;
-  fetchedAt: number;
-  digest: string;
-}
-
-export type SnapshotCacheRead<T> =
-  | { readonly outcome: 'hit'; readonly snapshot: FreshSnapshot<T> }
-  | { readonly outcome: 'miss' }
-  | { readonly outcome: 'invalidated'; readonly reason: InvalidationReason };
-
-export interface ReadSnapshotCacheOptions<T> {
-  readonly key: string;
-  readonly workspace: string;
-  readonly policy: FreshnessPolicy;
-  readonly validate: (value: unknown) => FreshPayload<T> | null;
-}
-
-function cacheKey(key: string): string {
-  return `${CACHE_PREFIX}:${key}`;
-}
-
-function isStoredSnapshot(value: unknown): value is StoredSnapshot {
-  if (typeof value !== 'object' || value === null) return false;
-  const candidate = value as Record<string, unknown>;
-  return (
-    typeof candidate['data'] === 'object' &&
-    candidate['data'] !== null &&
-    typeof candidate['source'] === 'string' &&
-    typeof candidate['workspace'] === 'string' &&
-    typeof candidate['version'] === 'number' &&
-    typeof candidate['schemaVersion'] === 'number' &&
-    typeof candidate['fetchedAt'] === 'number' &&
-    typeof candidate['digest'] === 'string'
-  );
-}
-
-function getStorage(): Storage | null {
-  try {
-    return globalThis.sessionStorage ?? null;
-  } catch {
-    return null;
-  }
-}
-
-/**
- * Restore a cached snapshot under the active workspace scope. Every failure
- * mode maps to an explicit invalidation reason or a miss — never to data
- * that renders as current.
- */
-export function readSnapshotCache<T>(options: ReadSnapshotCacheOptions<T>): SnapshotCacheRead<T> {
-  const storage = getStorage();
-  if (storage === null) return { outcome: 'miss' };
-
-  let raw: string | null;
-  try {
-    raw = storage.getItem(cacheKey(options.key));
-  } catch {
-    return { outcome: 'miss' };
-  }
-  if (raw === null) return { outcome: 'miss' };
-
-  let parsed: unknown;
-  try {
-    parsed = JSON.parse(raw);
-  } catch {
-    return { outcome: 'invalidated', reason: 'cache-corruption' };
-  }
-  if (!isStoredSnapshot(parsed)) {
-    return { outcome: 'invalidated', reason: 'cache-corruption' };
-  }
-  if (parsed.workspace !== options.workspace) {
-    return { outcome: 'invalidated', reason: 'cross-workspace' };
-  }
-  if (parsed.schemaVersion > options.policy.schemaVersion) {
-    // Written by a newer build than the running client: version regression.
-    return { outcome: 'invalidated', reason: 'version-regression' };
-  }
-
-  const payload = options.validate(parsed.data);
-  if (payload === null) {
-    return { outcome: 'invalidated', reason: 'schema-mismatch' };
-  }
-  if (computeDigest(payload.data) !== parsed.digest) {
-    return { outcome: 'invalidated', reason: 'cache-corruption' };
-  }
-
-  return {
-    outcome: 'hit',
-    snapshot: {
-      data: payload.data,
-      source: parsed.source,
-      workspace: parsed.workspace,
-      version: parsed.version,
-      schemaVersion: parsed.schemaVersion,
-      fetchedAt: parsed.fetchedAt,
-      digest: parsed.digest,
-    },
-  };
-}
-
-/** Persist a verified snapshot. Failures are non-fatal (cache is best-effort). */
-export function writeSnapshotCache<T>(key: string, snapshot: FreshSnapshot<T>): void {
-  const storage = getStorage();
-  if (storage === null) return;
-  const stored: StoredSnapshot = {
-    data: snapshot.data,
-    source: snapshot.source,
-    workspace: snapshot.workspace,
-    version: snapshot.version,
-    schemaVersion: snapshot.schemaVersion,
-    fetchedAt: snapshot.fetchedAt,
-    digest: snapshot.digest,
-  };
-  try {
-    storage.setItem(cacheKey(key), JSON.stringify(stored));
-  } catch {
-    // Quota or serialization failures simply skip caching.
-  }
-}
-
-/** Drop a cached snapshot (used when a surface invalidates its cache entry). */
-export function clearSnapshotCache(key: string): void {
-  const storage = getStorage();
-  if (storage === null) return;
-  try {
-    storage.removeItem(cacheKey(key));
-  } catch {
-    // Ignorable: a wedged storage entry is detected as corruption on read.
-  }
-}

apps/web/src/lib/freshness/use-fresh-collection.spec.tsx

@@ -1,372 +0,0 @@
-import { act } from 'react';
-import { createRoot, type Root } from 'react-dom/client';
-import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
-import type { Task } from '@/lib/types';
-import { acceptSnapshot, StaleMutationError, DEFAULT_FRESHNESS_POLICY } from './model';
-import type { FreshnessFailure } from './use-fresh-collection';
-import {
-  describeFailure,
-  useFreshCollection,
-  type FreshCollection,
-  type UseFreshCollectionOptions,
-} from './use-fresh-collection';
-import { validateProjectCollection, validateTaskCollection } from './validators';
-import { projectFixtures, taskFixtures } from '@/spa/pages/page-fixtures';
-
-/**
- * Failure-matrix coverage for the freshness seam (RI-5-001): network failure,
- * auth failure, malformed response, cache corruption, stale age, schema
- * mismatch, cross-workspace, recovery, and stale-action rejection — with
- * negative controls proving no case yields current data or an enabled
- * mutation.
- */
-
-const NOW = 1_800_000_000_000;
-
-interface Deferred<T> {
-  promise: Promise<T>;
-  resolve: (value: T) => void;
-  reject: (reason?: unknown) => void;
-}
-
-function createDeferred<T>(): Deferred<T> {
-  let resolve!: (value: T) => void;
-  let reject!: (reason?: unknown) => void;
-  const promise = new Promise<T>((res, rej) => {
-    resolve = res;
-    reject = rej;
-  });
-  return { promise, resolve, reject };
-}
-
-let root: Root | null = null;
-let container: HTMLDivElement;
-let latest: FreshCollection<Task[]> | null = null;
-
-function Probe({
-  options,
-}: {
-  options: UseFreshCollectionOptions<Task[]>;
-}): React.ReactElement | null {
-  latest = useFreshCollection<Task[]>(options);
-  return null;
-}
-
-beforeAll(() => {
-  Object.defineProperty(globalThis, 'IS_REACT_ACT_ENVIRONMENT', {
-    configurable: true,
-    value: true,
-  });
-});
-
-beforeEach(() => {
-  sessionStorage.clear();
-});
-
-afterEach(async () => {
-  await act(async () => {
-    root?.unmount();
-  });
-  document.body.replaceChildren();
-  root = null;
-  latest = null;
-  sessionStorage.clear();
-  vi.restoreAllMocks();
-});
-
-async function renderCollection(
-  options: UseFreshCollectionOptions<Task[]>,
-): Promise<FreshCollection<Task[]>> {
-  container = document.createElement('div');
-  document.body.append(container);
-  root = createRoot(container);
-  await act(async () => {
-    root?.render(<Probe options={options} />);
-  });
-  if (latest === null) throw new Error('hook did not run');
-  return latest;
-}
-
-function taskOptions(
-  overrides: Partial<UseFreshCollectionOptions<Task[]>> = {},
-): UseFreshCollectionOptions<Task[]> {
-  return {
-    source: 'gateway:/api/tasks',
-    fetcher: () => Promise.resolve(taskFixtures),
-    validate: validateTaskCollection,
-    cacheKey: 'tasks',
-    clock: () => NOW,
-    ...overrides,
-  };
-}
-
-function authError(statusCode: number): Error & { statusCode: number } {
-  return Object.assign(new Error(`Request failed with ${statusCode}`), { statusCode });
-}
-
-function seedCache(key: string): number {
-  const result = acceptSnapshot({
-    value: taskFixtures,
-    validate: validateTaskCollection,
-    previous: null,
-    policy: DEFAULT_FRESHNESS_POLICY,
-    source: 'gateway:/api/tasks',
-    now: NOW,
-  });
-  if (result.outcome !== 'accepted') throw new Error('fixture setup failed');
-  sessionStorage.setItem(`mosaic:freshness:v1:${key}`, JSON.stringify({ ...result.snapshot }));
-  return result.snapshot.version;
-}
-
-describe('useFreshCollection failure matrix', () => {
-  it('is unknown (not empty) while the first validation is in flight', async () => {
-    const deferred = createDeferred<Task[]>();
-    const collection = await renderCollection(taskOptions({ fetcher: () => deferred.promise }));
-
-    expect(collection.freshness).toBe('unknown');
-    expect(collection.validating).toBe(true);
-    expect(collection.data).toBeNull();
-    expect(collection.canMutate).toBe(false);
-
-    await act(async () => {
-      deferred.resolve(taskFixtures);
-      await deferred.promise;
-    });
-  });
-
-  it('becomes current with provenance after a verified fetch', async () => {
-    const collection = await renderCollection(taskOptions());
-
-    expect(collection.freshness).toBe('current');
-    expect(collection.data).toEqual(taskFixtures);
-    expect(collection.snapshot?.source).toBe('gateway:/api/tasks');
-    expect(collection.snapshot?.version).toBe(1);
-    expect(collection.failure).toBeNull();
-    expect(collection.canMutate).toBe(true);
-    // Verified snapshot is persisted for last-known restore.
-    expect(sessionStorage.getItem('mosaic:freshness:v1:tasks')).toBeTruthy();
-  });
-
-  it('treats a network failure as unavailable — never an empty healthy collection', async () => {
-    const collection = await renderCollection(
-      taskOptions({ fetcher: () => Promise.reject(new Error('network down')) }),
-    );
-
-    expect(collection.freshness).toBe('unavailable');
-    expect(collection.data).toBeNull();
-    expect(collection.failure).toEqual({ kind: 'fetch', message: 'network down' });
-    expect(collection.canMutate).toBe(false);
-    expect(describeFailure(collection.failure)).toBe('network down');
-  });
-
-  it('treats an auth failure as unavailable and drops the last-known snapshot', async () => {
-    let call = 0;
-    const collection = await renderCollection(
-      taskOptions({
-        fetcher: () => {
-          call += 1;
-          return call === 1 ? Promise.resolve(taskFixtures) : Promise.reject(authError(401));
-        },
-      }),
-    );
-    expect(collection.freshness).toBe('current');
-
-    await act(async () => {
-      await collection.revalidate();
-    });
-
-    expect(latest?.freshness).toBe('unavailable');
-    expect(latest?.data).toBeNull();
-    expect(latest?.failure?.kind).toBe('fetch');
-    // The previous user's data must not linger in the session cache.
-    expect(sessionStorage.getItem('mosaic:freshness:v1:tasks')).toBeNull();
-  });
-
-  it('invalidates a malformed response as a schema mismatch', async () => {
-    const collection = await renderCollection(
-      taskOptions({ fetcher: () => Promise.resolve({ malformed: true }) }),
-    );
-
-    expect(collection.freshness).toBe('unavailable');
-    expect(collection.data).toBeNull();
-    expect(collection.failure).toEqual({ kind: 'invalidated', reason: 'schema-mismatch' });
-    expect(collection.canMutate).toBe(false);
-  });
-
-  it('keeps the previous snapshot as labeled stale when a later payload mismatches', async () => {
-    let call = 0;
-    const collection = await renderCollection(
-      taskOptions({
-        fetcher: () => {
-          call += 1;
-          return call === 1 ? Promise.resolve(taskFixtures) : Promise.resolve('garbage');
-        },
-      }),
-    );
-    expect(collection.freshness).toBe('current');
-
-    await act(async () => {
-      await collection.revalidate();
-    });
-
-    expect(latest?.freshness).toBe('stale');
-    expect(latest?.data).toEqual(taskFixtures);
-    expect(latest?.failure).toEqual({ kind: 'invalidated', reason: 'schema-mismatch' });
-    expect(latest?.canMutate).toBe(false);
-  });
-
-  it('drops the snapshot when the workspace changes under it (cross-workspace)', async () => {
-    let call = 0;
-    const collection = await renderCollection(
-      taskOptions({
-        fetcher: () => {
-          call += 1;
-          return Promise.resolve(
-            call === 1 ? projectFixtures : [{ ...projectFixtures[0], userId: 'user-2' }],
-          );
-        },
-        validate: validateProjectCollection as unknown as (value: unknown) => {
-          data: Task[];
-          workspace: string | null;
-        },
-        source: 'gateway:/api/projects',
-      }),
-    );
-    expect(collection.freshness).toBe('current');
-
-    await act(async () => {
-      await collection.revalidate();
-    });
-
-    expect(latest?.freshness).toBe('unavailable');
-    expect(latest?.data).toBeNull();
-    expect(latest?.failure).toEqual({ kind: 'invalidated', reason: 'cross-workspace' });
-  });
-
-  it('ages from current to stale and refuses mutations on stale data', async () => {
-    let fakeNow = NOW;
-    const collection = await renderCollection(
-      taskOptions({
-        clock: () => fakeNow,
-        policy: { staleAfterMs: 40 },
-        tickMs: 10,
-      }),
-    );
-    expect(collection.freshness).toBe('current');
-
-    // Age the snapshot past the policy and let the tick recompute.
-    fakeNow = NOW + 60;
-    await act(async () => {
-      await new Promise((resolve) => setTimeout(resolve, 25));
-    });
-
-    expect(latest?.freshness).toBe('stale');
-    expect(latest?.data).toEqual(taskFixtures);
-    expect(latest?.canMutate).toBe(false);
-
-    const operation = vi.fn(async () => 'result');
-    await expect(latest?.mutate(operation)).rejects.toBeInstanceOf(StaleMutationError);
-    expect(operation).not.toHaveBeenCalled();
-  });
-
-  it('recovers to current after a successful revalidation', async () => {
-    let call = 0;
-    const collection = await renderCollection(
-      taskOptions({
-        fetcher: () => {
-          call += 1;
-          return call === 1
-            ? Promise.reject(new Error('first attempt failed'))
-            : Promise.resolve(taskFixtures);
-        },
-      }),
-    );
-    expect(collection.freshness).toBe('unavailable');
-
-    await act(async () => {
-      await collection.revalidate();
-    });
-
-    expect(latest?.freshness).toBe('current');
-    expect(latest?.failure).toBeNull();
-
-    const operation = vi.fn(async (data: Task[]) => data.length);
-    await expect(latest?.mutate(operation)).resolves.toBe(taskFixtures.length);
-    expect(operation).toHaveBeenCalledOnce();
-  });
-
-  it('restores a cached snapshot as unverified stale data, then verifies it', async () => {
-    const seededVersion = seedCache('tasks');
-    const deferred = createDeferred<Task[]>();
-    const collection = await renderCollection(taskOptions({ fetcher: () => deferred.promise }));
-
-    // Restored data is situational awareness only: labeled stale, never
-    // current, and mutations are refused before verification.
-    expect(collection.freshness).toBe('stale');
-    expect(collection.data).toEqual(taskFixtures);
-    expect(collection.canMutate).toBe(false);
-    await expect(collection.mutate(vi.fn())).rejects.toBeInstanceOf(StaleMutationError);
-
-    await act(async () => {
-      deferred.resolve(taskFixtures);
-      await deferred.promise;
-    });
-
-    expect(latest?.freshness).toBe('current');
-    expect(latest?.snapshot?.version).toBe(seededVersion + 1);
-  });
-
-  it('never promotes corrupted cache data to current (cache corruption)', async () => {
-    sessionStorage.setItem('mosaic:freshness:v1:tasks', '{"data":');
-    const collection = await renderCollection(
-      taskOptions({ fetcher: () => Promise.reject(new Error('still down')) }),
-    );
-
-    expect(collection.freshness).toBe('unavailable');
-    expect(collection.data).toBeNull();
-    expect(collection.canMutate).toBe(false);
-    // The corrupted entry is dropped so it cannot come back.
-    expect(sessionStorage.getItem('mosaic:freshness:v1:tasks')).toBeNull();
-  });
-
-  it('refuses mutations while unknown or unavailable — the call itself, not just the button', async () => {
-    const deferred = createDeferred<Task[]>();
-    const unknown = await renderCollection(taskOptions({ fetcher: () => deferred.promise }));
-    const operation = vi.fn(async () => 'result');
-    await expect(unknown.mutate(operation)).rejects.toBeInstanceOf(StaleMutationError);
-    expect(operation).not.toHaveBeenCalled();
-    await act(async () => {
-      deferred.reject(new Error('failed'));
-      await deferred.promise.catch(() => undefined);
-    });
-
-    const unavailable = latest!;
-    await expect(unavailable.mutate(operation)).rejects.toBeInstanceOf(StaleMutationError);
-    expect(operation).not.toHaveBeenCalled();
-    expect(unavailable.canMutate).toBe(false);
-  });
-
-  it('degrades to stale with last-known data when a revalidation fails after success', async () => {
-    let call = 0;
-    const collection = await renderCollection(
-      taskOptions({
-        fetcher: () => {
-          call += 1;
-          return call === 1
-            ? Promise.resolve(taskFixtures)
-            : Promise.reject(new Error('connection lost'));
-        },
-      }),
-    );
-    expect(collection.freshness).toBe('current');
-
-    await act(async () => {
-      await collection.revalidate();
-    });
-
-    expect(latest?.freshness).toBe('stale');
-    expect(latest?.data).toEqual(taskFixtures);
-    const failure: FreshnessFailure | null = latest?.failure ?? null;
-    expect(failure).toEqual({ kind: 'fetch', message: 'connection lost' });
-  });
-});

apps/web/src/lib/freshness/use-fresh-collection.ts

@@ -1,281 +0,0 @@
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
-import {
-  acceptSnapshot,
-  assertMutable,
-  computeFreshness,
-  DEFAULT_FRESHNESS_POLICY,
-  invalidationReasonLabels,
-  type FreshPayload,
-  type FreshSnapshot,
-  type FreshnessPolicy,
-  type FreshnessState,
-  type InvalidationReason,
-  StaleMutationError,
-} from './model';
-import { clearSnapshotCache, readSnapshotCache, writeSnapshotCache } from './snapshot-cache';
-
-/**
- * Freshness-aware collection fetch hook (RI-5-001).
- *
- * One hook owns one gateway collection end to end: fetch, schema validation,
- * snapshot acceptance with provenance, session-scoped last-known caching,
- * aging, and the mutation guard. Pages consume `freshness` and never infer
- * health from emptiness.
- */
-
-/** Why the latest validation did not produce a current snapshot. */
-export type FreshnessFailure =
-  | { readonly kind: 'fetch'; readonly message: string }
-  | { readonly kind: 'invalidated'; readonly reason: InvalidationReason };
-
-export interface UseFreshCollectionOptions<T> {
-  /** Source identity for provenance labels, e.g. `gateway:/api/tasks`. */
-  readonly source: string;
-  /** Performs the unvalidated fetch. The hook owns abort and verification. */
-  readonly fetcher: (signal: AbortSignal) => Promise<unknown>;
-  /**
-   * Runtime schema validator. Returning `null` invalidates the payload
-   * (`schema-mismatch`) instead of letting malformed JSON flow into render.
-   */
-  readonly validate: (value: unknown) => FreshPayload<T> | null;
-  /** Overrides of the default freshness policy. */
-  readonly policy?: Partial<FreshnessPolicy>;
-  /**
-   * Session cache key for last-known snapshots. `null`/omitted disables
-   * restore. Restored snapshots are unverified: they render only as
-   * labeled `stale` data until a fetch re-verifies them.
-   */
-  readonly cacheKey?: string | null;
-  /** Injectable clock for deterministic age transitions in tests. */
-  readonly clock?: () => number;
-  /** Aging tick interval override (default derived from `staleAfterMs`). */
-  readonly tickMs?: number;
-  /** When false, no fetch runs (surfaces stay `unavailable`/`unknown`). */
-  readonly enabled?: boolean;
-}
-
-export interface FreshCollection<T> {
-  /** Last verified (or restored-unverified) snapshot, or `null`. */
-  readonly snapshot: FreshSnapshot<T> | null;
-  /** Snapshot data or `null` — never a fabricated empty collection. */
-  readonly data: T | null;
-  readonly freshness: FreshnessState;
-  /** True while a validation request is in flight. */
-  readonly validating: boolean;
-  /** Outcome of the latest failed validation, `null` when healthy. */
-  readonly failure: FreshnessFailure | null;
-  /** False unless freshness is `current`; drives disabled UI affordances. */
-  readonly canMutate: boolean;
-  /** Re-run the fetch and re-verify. Always allowed (it is a read). */
-  readonly revalidate: () => Promise<void>;
-  /**
-   * Run a state-changing operation against verified-current data only.
-   * Rejects with `StaleMutationError` on any other state — the guard fires
-   * even if a disabled button was bypassed (defense in depth).
-   */
-  readonly mutate: <R>(operation: (data: T) => Promise<R>) => Promise<R>;
-}
-
-const defaultClock = (): number => Date.now();
-
-function resolveTickMs(policy: FreshnessPolicy, override?: number): number {
-  if (override !== undefined && override > 0) return override;
-  return Math.min(5_000, Math.max(250, Math.floor(policy.staleAfterMs / 4)));
-}
-
-function isAuthFailure(caught: unknown): boolean {
-  return (
-    typeof caught === 'object' &&
-    caught !== null &&
-    'statusCode' in caught &&
-    ((caught as { statusCode?: unknown }).statusCode === 401 ||
-      (caught as { statusCode?: unknown }).statusCode === 403)
-  );
-}
-
-function fetchFailureMessage(caught: unknown): string {
-  if (caught instanceof Error && caught.message.trim().length > 0) return caught.message;
-  return 'The request failed.';
-}
-
-/** Human-readable summary of a failure for unavailable/stale notices. */
-export function describeFailure(failure: FreshnessFailure | null): string | null {
-  if (failure === null) return null;
-  if (failure.kind === 'fetch') return failure.message;
-  return `The snapshot was invalidated: ${invalidationReasonLabels[failure.reason]}.`;
-}
-
-export function useFreshCollection<T>(options: UseFreshCollectionOptions<T>): FreshCollection<T> {
-  const optionsRef = useRef(options);
-  optionsRef.current = options;
-
-  const policy = useMemo<FreshnessPolicy>(
-    () => ({ ...DEFAULT_FRESHNESS_POLICY, ...options.policy }),
-    [options.policy],
-  );
-  const policyRef = useRef(policy);
-  policyRef.current = policy;
-
-  const clockRef = useRef(options.clock ?? defaultClock);
-  clockRef.current = options.clock ?? defaultClock;
-
-  const [snapshot, setSnapshot] = useState<FreshSnapshot<T> | null>(null);
-  const [failure, setFailure] = useState<FreshnessFailure | null>(null);
-  const [unverified, setUnverified] = useState(false);
-  const [validating, setValidating] = useState(options.enabled !== false);
-  const [now, setNow] = useState(() => (options.clock ?? defaultClock)());
-
-  const snapshotRef = useRef(snapshot);
-  snapshotRef.current = snapshot;
-  const failureRef = useRef(failure);
-  failureRef.current = failure;
-  const unverifiedRef = useRef(unverified);
-  unverifiedRef.current = unverified;
-
-  const runRef = useRef(0);
-  const abortRef = useRef<AbortController | null>(null);
-
-  const revalidate = useCallback(async (): Promise<void> => {
-    const current = optionsRef.current;
-    if (current.enabled === false) {
-      setValidating(false);
-      return;
-    }
-
-    const runId = ++runRef.current;
-    abortRef.current?.abort();
-    const controller = new AbortController();
-    abortRef.current = controller;
-    setValidating(true);
-
-    let value: unknown;
-    try {
-      value = await current.fetcher(controller.signal);
-    } catch (caught) {
-      if (runRef.current !== runId || controller.signal.aborted) return;
-      if (isAuthFailure(caught)) {
-        // An unauthenticated viewer must not keep (or be served) the
-        // previous user's last-known data.
-        setSnapshot(null);
-        setUnverified(false);
-        if (current.cacheKey) clearSnapshotCache(current.cacheKey);
-      }
-      setFailure({ kind: 'fetch', message: fetchFailureMessage(caught) });
-      setValidating(false);
-      return;
-    }
-
-    if (runRef.current !== runId) return;
-
-    const result = acceptSnapshot({
-      value,
-      validate: current.validate,
-      previous: snapshotRef.current,
-      policy: policyRef.current,
-      source: current.source,
-      now: clockRef.current(),
-    });
-
-    if (result.outcome === 'accepted') {
-      setSnapshot(result.snapshot);
-      setUnverified(false);
-      setFailure(null);
-      if (current.cacheKey) writeSnapshotCache(current.cacheKey, result.snapshot);
-    } else {
-      if (result.reason === 'cross-workspace') {
-        // Data verified for a different workspace must not linger as
-        // last-known situational awareness either.
-        setSnapshot(null);
-        setUnverified(false);
-      }
-      if (current.cacheKey) clearSnapshotCache(current.cacheKey);
-      setFailure({ kind: 'invalidated', reason: result.reason });
-    }
-    setValidating(false);
-  }, []);
-
-  // Restore the last-known snapshot (unverified) and run the first fetch.
-  useEffect(() => {
-    if (optionsRef.current.enabled === false) {
-      setValidating(false);
-      return;
-    }
-
-    const cacheKey = optionsRef.current.cacheKey;
-    if (cacheKey) {
-      const restored = readSnapshotCache<T>({
-        key: cacheKey,
-        workspace: policyRef.current.workspace,
-        policy: policyRef.current,
-        validate: optionsRef.current.validate,
-      });
-      if (restored.outcome === 'hit') {
-        setSnapshot(restored.snapshot);
-        setUnverified(true);
-      } else if (restored.outcome === 'invalidated') {
-        // A corrupted/foreign/regressed entry is dropped immediately; it must
-        // never surface as data. The fetch decides the visible state.
-        clearSnapshotCache(cacheKey);
-      }
-    }
-
-    void revalidate();
-
-    return () => {
-      abortRef.current?.abort();
-    };
-    // Mount-once by design: `revalidate` is stable and reads live options
-    // through refs, so it never needs to re-run when options change.
-    // Route-param pages remount this hook via an identity `key` instead.
-  }, [revalidate]);
-
-  // Aging tick: recomputes freshness as the snapshot ages past the policy.
-  useEffect(() => {
-    const interval = setInterval(
-      () => {
-        setNow(clockRef.current());
-      },
-      resolveTickMs(policyRef.current, optionsRef.current.tickMs),
-    );
-    return () => clearInterval(interval);
-  }, []);
-
-  const freshness = useMemo<FreshnessState>(() => {
-    if (snapshot === null) return validating ? 'unknown' : 'unavailable';
-    return computeFreshness({
-      snapshot,
-      policy,
-      now,
-      degraded: failure !== null || unverified,
-    });
-    // `now` from state covers age; refs inside computeFreshness are pure.
-  }, [snapshot, validating, failure, unverified, now, policy]);
-
-  const canMutate = freshness === 'current';
-
-  const mutate = useCallback(async <R>(operation: (data: T) => Promise<R>): Promise<R> => {
-    const currentSnapshot = snapshotRef.current;
-    // No verified snapshot at all: with nothing verified there is nothing
-    // current to mutate, regardless of the recorded failure.
-    if (currentSnapshot === null) throw new StaleMutationError('unavailable');
-    const state = computeFreshness({
-      snapshot: currentSnapshot,
-      policy: policyRef.current,
-      now: clockRef.current(),
-      degraded: failureRef.current !== null || unverifiedRef.current,
-    });
-    assertMutable(state);
-    return operation(currentSnapshot.data);
-  }, []);
-
-  return {
-    snapshot,
-    data: snapshot === null ? null : snapshot.data,
-    freshness,
-    validating,
-    failure,
-    canMutate,
-    revalidate,
-    mutate,
-  };
-}

apps/web/src/lib/freshness/validators.spec.ts

@@ -1,103 +0,0 @@
-import { describe, expect, it } from 'vitest';
-import type { Mission, Project, Task } from '@/lib/types';
-import {
-  validateMissionCollection,
-  validateProjectCollection,
-  validateProjectEntity,
-  validateTaskCollection,
-} from './validators';
-import { missionFixtures, projectFixtures, taskFixtures } from '@/spa/pages/page-fixtures';
-
-describe('validateTaskCollection', () => {
-  it('accepts a well-formed task collection', () => {
-    expect(validateTaskCollection(taskFixtures)).toEqual({
-      data: taskFixtures,
-      workspace: null,
-    });
-  });
-
-  it('accepts an empty collection (a healthy empty state is a valid payload)', () => {
-    expect(validateTaskCollection([])).toEqual({ data: [], workspace: null });
-  });
-
-  it.each([
-    ['not an array', { items: [] }],
-    ['item is not an object', ['nope']],
-    ['missing id', [{ ...(taskFixtures[0] as Task), id: undefined }]],
-    ['missing title', [{ ...(taskFixtures[0] as Task), title: undefined }]],
-    ['unknown status enum', [{ ...(taskFixtures[0] as Task), status: 'finished' }]],
-    ['unknown priority enum', [{ ...(taskFixtures[0] as Task), priority: 'urgent' }]],
-    ['tags of the wrong type', [{ ...(taskFixtures[0] as Task), tags: 'spa' }]],
-    ['metadata of the wrong type', [{ ...(taskFixtures[0] as Task), metadata: 'notes' }]],
-    ['createdAt of the wrong type', [{ ...(taskFixtures[0] as Task), createdAt: 1234 }]],
-    ['null sneaks past a required string', [{ ...(taskFixtures[0] as Task), title: null }]],
-  ])('rejects a malformed payload: %s', (_label, value) => {
-    expect(validateTaskCollection(value)).toBeNull();
-  });
-});
-
-describe('validateMissionCollection', () => {
-  it('accepts a well-formed mission collection', () => {
-    expect(validateMissionCollection(missionFixtures)).toEqual({
-      data: missionFixtures,
-      workspace: null,
-    });
-  });
-
-  it.each([
-    ['not an array', null],
-    ['item missing name', [{ ...(missionFixtures[0] as Mission), name: 42 }]],
-    ['unknown status enum', [{ ...(missionFixtures[0] as Mission), status: 'canceled' }]],
-    ['projectId of the wrong type', [{ ...(missionFixtures[0] as Mission), projectId: 7 }]],
-  ])('rejects a malformed payload: %s', (_label, value) => {
-    expect(validateMissionCollection(value)).toBeNull();
-  });
-});
-
-describe('validateProjectCollection', () => {
-  it('accepts a uniform workspace-scoped collection and reports its workspace', () => {
-    expect(validateProjectCollection(projectFixtures)).toEqual({
-      data: projectFixtures,
-      workspace: 'user-1',
-    });
-  });
-
-  it('accepts an empty collection with no workspace identity', () => {
-    expect(validateProjectCollection([])).toEqual({ data: [], workspace: null });
-  });
-
-  it.each([
-    ['not an array', 42],
-    ['item missing userId', [{ ...(projectFixtures[0] as Project), userId: undefined }]],
-    ['unknown status enum', [{ ...(projectFixtures[0] as Project), status: 'live' }]],
-    ['description of the wrong type', [{ ...(projectFixtures[0] as Project), description: 1 }]],
-  ])('rejects a malformed payload: %s', (_label, value) => {
-    expect(validateProjectCollection(value)).toBeNull();
-  });
-
-  it('rejects a collection mixing workspace identities (cross-workspace leak)', () => {
-    const mixed = [
-      projectFixtures[0] as Project,
-      { ...(projectFixtures[1] as Project), userId: 'user-2' },
-    ];
-    expect(validateProjectCollection(mixed)).toBeNull();
-  });
-});
-
-describe('validateProjectEntity', () => {
-  it('accepts a well-formed project and reports its workspace', () => {
-    expect(validateProjectEntity(projectFixtures[0])).toEqual({
-      data: projectFixtures[0],
-      workspace: 'user-1',
-    });
-  });
-
-  it.each([
-    ['not an object', 'project-1'],
-    ['null', null],
-    ['array', [projectFixtures[0]]],
-    ['missing userId', [{ ...(projectFixtures[0] as Project), userId: null }]],
-  ])('rejects a malformed entity: %s', (_label, value) => {
-    expect(validateProjectEntity(value)).toBeNull();
-  });
-});

apps/web/src/lib/freshness/validators.ts

@@ -1,135 +0,0 @@
-import type { Mission, Project, Task, MissionStatus, TaskPriority, TaskStatus } from '@/lib/types';
-import type { FreshPayload } from './model';
-
-/**
- * Runtime schema validators for gateway collections (RI-5-001).
- *
- * `api<T>()` returns untrusted JSON cast to `T`; these validators are the
- * seam where a malformed response becomes an explicit schema mismatch
- * instead of flowing into the render path as if it were healthy data.
- */
-
-const taskStatuses: readonly TaskStatus[] = [
-  'not-started',
-  'in-progress',
-  'blocked',
-  'done',
-  'cancelled',
-];
-const taskPriorities: readonly TaskPriority[] = ['critical', 'high', 'medium', 'low'];
-const missionStatuses: readonly MissionStatus[] = [
-  'planning',
-  'active',
-  'paused',
-  'completed',
-  'failed',
-];
-const projectStatuses: readonly Project['status'][] = ['active', 'paused', 'completed', 'archived'];
-
-function isRecord(value: unknown): value is Record<string, unknown> {
-  return typeof value === 'object' && value !== null && !Array.isArray(value);
-}
-
-function isString(value: unknown): value is string {
-  return typeof value === 'string';
-}
-
-function isNullableString(value: unknown): value is string | null {
-  return value === null || typeof value === 'string';
-}
-
-function isOneOf<T extends string>(value: unknown, allowed: readonly T[]): value is T {
-  return typeof value === 'string' && (allowed as readonly string[]).includes(value);
-}
-
-function isNullableRecord(value: unknown): value is Record<string, unknown> | null {
-  return value === null || isRecord(value);
-}
-
-function isNullableStringArray(value: unknown): value is string[] | null {
-  if (value === null) return true;
-  if (!Array.isArray(value)) return false;
-  return value.every((item) => typeof item === 'string');
-}
-
-function isIsoLike(value: unknown): value is string {
-  return typeof value === 'string' && value.length > 0;
-}
-
-function isTask(value: unknown): value is Task {
-  if (!isRecord(value)) return false;
-  return (
-    isString(value['id']) &&
-    isString(value['title']) &&
-    isOneOf(value['status'], taskStatuses) &&
-    isOneOf(value['priority'], taskPriorities) &&
-    isNullableString(value['projectId']) &&
-    isNullableString(value['missionId']) &&
-    isNullableString(value['assignee']) &&
-    isNullableStringArray(value['tags']) &&
-    isNullableRecord(value['metadata']) &&
-    isNullableString(value['dueDate']) &&
-    isIsoLike(value['createdAt']) &&
-    isIsoLike(value['updatedAt'])
-  );
-}
-
-/** Tasks carry no workspace identity; scope falls back to the policy. */
-export function validateTaskCollection(value: unknown): FreshPayload<Task[]> | null {
-  if (!Array.isArray(value) || !value.every(isTask)) return null;
-  return { data: value as Task[], workspace: null };
-}
-
-function isMission(value: unknown): value is Mission {
-  if (!isRecord(value)) return false;
-  return (
-    isString(value['id']) &&
-    isString(value['name']) &&
-    isOneOf(value['status'], missionStatuses) &&
-    isNullableString(value['projectId']) &&
-    isNullableString(value['description']) &&
-    isNullableRecord(value['metadata']) &&
-    isIsoLike(value['createdAt']) &&
-    isIsoLike(value['updatedAt'])
-  );
-}
-
-/** Missions carry no workspace identity; scope falls back to the policy. */
-export function validateMissionCollection(value: unknown): FreshPayload<Mission[]> | null {
-  if (!Array.isArray(value) || !value.every(isMission)) return null;
-  return { data: value as Mission[], workspace: null };
-}
-
-function isProject(value: unknown): value is Project {
-  if (!isRecord(value)) return false;
-  return (
-    isString(value['id']) &&
-    isString(value['name']) &&
-    isOneOf(value['status'], projectStatuses) &&
-    isString(value['userId']) &&
-    isNullableString(value['description']) &&
-    isNullableRecord(value['metadata']) &&
-    isIsoLike(value['createdAt']) &&
-    isIsoLike(value['updatedAt'])
-  );
-}
-
-/**
- * Projects are workspace-scoped: every item must carry the same `userId`.
- * A collection mixing identities (cross-workspace leak) is a schema
- * mismatch; the uniform `userId` becomes the snapshot workspace.
- */
-export function validateProjectCollection(value: unknown): FreshPayload<Project[]> | null {
-  if (!Array.isArray(value) || !value.every(isProject)) return null;
-  const projects = value as Project[];
-  const workspaces = new Set(projects.map((project) => project.userId));
-  if (workspaces.size > 1) return null;
-  return { data: projects, workspace: projects.length > 0 ? projects[0]!.userId : null };
-}
-
-/** Single project entity (project detail primary collection). */
-export function validateProjectEntity(value: unknown): FreshPayload<Project> | null {
-  if (!isProject(value)) return null;
-  const project = value as Project;
-  return { data: project, workspace: project.userId };
-}

apps/web/src/spa/pages/project-detail.spec.tsx

@@ -35,7 +35,6 @@ afterEach(async () => {
   document.body.replaceChildren();
   root = null;
   apiMock.mockReset();
-  sessionStorage.clear();
 });
 
 async function renderProjectDetailPage(): Promise<ReturnType<typeof createMemoryRouter>> {
@@ -65,49 +64,21 @@ function clickButtonByText(text: string): void {
   button.dispatchEvent(new MouseEvent('click', { bubbles: true }));
 }
 
-async function flushAct(): Promise<void> {
-  await act(async () => {
-    await Promise.resolve();
-  });
-}
-
-interface Deferred<T> {
-  promise: Promise<T>;
-  resolve: (value: T) => void;
-}
-
-function createDeferred<T>(): Deferred<T> {
-  let resolve!: (value: T) => void;
-  const promise = new Promise<T>((res) => {
-    resolve = res;
-  });
-  return { promise, resolve };
-}
-
-const projectOneTasks = taskFixtures.filter((task) => task.projectId === 'project-1');
-
-function mockHealthyLoad(): void {
-  apiMock
-    .mockResolvedValueOnce(projectFixtures[0])
-    .mockResolvedValueOnce(missionFixtures)
-    .mockResolvedValueOnce(projectOneTasks);
-}
-
 describe('ProjectDetailPage', () => {
   it('loads the project, tasks, missions, and optional PRD content for the active project', async () => {
-    mockHealthyLoad();
+    apiMock
+      .mockResolvedValueOnce(projectFixtures[0])
+      .mockResolvedValueOnce(missionFixtures)
+      .mockResolvedValueOnce(taskFixtures.filter((task) => task.projectId === 'project-1'));
 
     await renderProjectDetailPage();
 
-    expect(apiMock.mock.calls.map((call) => call[0])).toEqual([
-      '/api/projects/project-1',
-      '/api/missions',
-      '/api/tasks?projectId=project-1',
+    expect(apiMock.mock.calls).toEqual([
+      ['/api/projects/project-1'],
+      ['/api/missions'],
+      ['/api/tasks?projectId=project-1'],
     ]);
 
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'current',
-    );
     expect(container.textContent).toContain('Mosaic Stack');
     expect(container.textContent).toContain('Route /projects/:id');
     expect(container.textContent).toContain('Tasks');
@@ -130,7 +101,10 @@ describe('ProjectDetailPage', () => {
   });
 
   it('opens and closes the existing read-only task modal from the tasks tab', async () => {
-    mockHealthyLoad();
+    apiMock
+      .mockResolvedValueOnce(projectFixtures[0])
+      .mockResolvedValueOnce(missionFixtures)
+      .mockResolvedValueOnce(taskFixtures.filter((task) => task.projectId === 'project-1'));
 
     await renderProjectDetailPage();
 
@@ -160,153 +134,35 @@ describe('ProjectDetailPage', () => {
     expect(container.querySelector('[role="dialog"]')).toBeNull();
   });
 
-  it('shows verified completion verdicts when the task collection is current', async () => {
-    mockHealthyLoad();
-
-    await renderProjectDetailPage();
-
-    const doneCard = [...container.querySelectorAll('div')].find(
-      (candidate) => candidate.textContent === 'Done1',
-    );
-    expect(doneCard).toBeTruthy();
-    const inProgressCard = [...container.querySelectorAll('div')].find(
-      (candidate) => candidate.textContent === 'In Progress1',
-    );
-    expect(inProgressCard).toBeTruthy();
-  });
-
-  it('renders an explicit unavailable missions tab when the missions request fails (partial, not empty)', async () => {
+  it('renders the project with an empty missions tab when the missions request fails', async () => {
     apiMock
       .mockResolvedValueOnce(projectFixtures[0])
       .mockRejectedValueOnce(new Error('Missions request failed'))
-      .mockResolvedValueOnce(projectOneTasks);
+      .mockResolvedValueOnce(taskFixtures.filter((task) => task.projectId === 'project-1'));
 
     await renderProjectDetailPage();
 
-    // Secondary failure degrades the surface to partial; the project itself
-    // still renders.
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'partial',
-    );
     expect(container.textContent).toContain('Mosaic Stack');
-    const partial = container.querySelector('[role="status"]');
-    expect(partial?.textContent).toContain('Missions');
-    expect(partial?.textContent).toContain('unavailable');
+    expect(container.querySelector('[role="alert"]')).toBeNull();
 
     await act(async () => {
-      clickButtonByText('Missions (?)');
+      clickButtonByText('Missions (0)');
     });
 
-    const alert = container.querySelector('[role="alert"]');
-    expect(alert?.textContent).toContain('Missions request failed');
-    // Negative control: a failed fetch must not look like an empty list.
-    expect(container.textContent).not.toContain('No missions for this project');
+    expect(container.textContent).toContain('No missions for this project');
   });
 
-  it('marks derived verdicts unknown when the tasks collection is unavailable', async () => {
-    apiMock
-      .mockResolvedValueOnce(projectFixtures[0])
-      .mockResolvedValueOnce(missionFixtures)
-      .mockRejectedValueOnce(new Error('Tasks request failed'));
-
-    await renderProjectDetailPage();
-
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'partial',
-    );
-
-    // Completion verdicts become unknown ('?') — never green counts.
-    for (const label of ['Done', 'In Progress', 'Blocked', 'Tasks']) {
-      const unknownCard = [...container.querySelectorAll('div')].find(
-        (candidate) => candidate.textContent === `${label}?`,
-      );
-      expect(unknownCard, `expected ${label} card to render ?`).toBeTruthy();
-    }
-    // Negative control: no green "Done 1" verdict anywhere.
-    expect(
-      [...container.querySelectorAll('div')].some((candidate) => candidate.textContent === 'Done1'),
-    ).toBe(false);
-
-    await act(async () => {
-      clickButtonByText('Tasks (?)');
-    });
-
-    const alert = container.querySelector('[role="alert"]');
-    expect(alert?.textContent).toContain('Tasks request failed');
-    // Negative control: no healthy empty task list from a failed fetch.
-    expect(container.textContent).not.toContain('No tasks found');
-    expect(container.querySelector('table')).toBeNull();
-  });
-
-  it('recovers a partial surface to current after revalidation', async () => {
-    apiMock
-      .mockResolvedValueOnce(projectFixtures[0])
-      .mockResolvedValueOnce(missionFixtures)
-      .mockRejectedValueOnce(new Error('Tasks request failed'))
-      .mockResolvedValueOnce(projectFixtures[0])
-      .mockResolvedValueOnce(missionFixtures)
-      .mockResolvedValueOnce(projectOneTasks);
-
-    await renderProjectDetailPage();
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'partial',
-    );
-
-    await act(async () => {
-      clickButtonByText('Revalidate');
-    });
-    await flushAct();
-
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'current',
-    );
-    expect(
-      [...container.querySelectorAll('div')].some((candidate) => candidate.textContent === 'Done1'),
-    ).toBe(true);
-  });
-
-  it("never shows one project's data on another project's route after navigation", async () => {
-    mockHealthyLoad();
-
-    const router = await renderProjectDetailPage();
-    expect(container.textContent).toContain('Mosaic Stack');
-
-    const deferred = createDeferred<(typeof projectFixtures)[number]>();
-    apiMock
-      .mockResolvedValueOnce(deferred.promise)
-      .mockResolvedValueOnce([])
-      .mockResolvedValueOnce([]);
-
-    await act(async () => {
-      await router.navigate('/projects/project-2');
-    });
-
-    // While project-2 loads, nothing from project-1 may render on its route.
-    expect(container.textContent).toContain('Loading project...');
-    expect(container.textContent).not.toContain('Mosaic Stack');
-    expect(container.textContent).not.toContain('Route /projects/:id');
-
-    await act(async () => {
-      deferred.resolve(projectFixtures[1]!);
-      await deferred.promise;
-    });
-
-    expect(container.textContent).toContain('Agent Runtime');
-    expect(apiMock.mock.calls[3]?.[0]).toBe('/api/projects/project-2');
-  });
-
-  it('renders a visible unavailable state when the project request fails and lets the user navigate back', async () => {
+  it('renders a visible alert when the project request fails and lets the user navigate back', async () => {
     apiMock
       .mockRejectedValueOnce(new Error('Project request failed'))
       .mockResolvedValueOnce(missionFixtures)
-      .mockResolvedValueOnce(projectOneTasks);
+      .mockResolvedValueOnce(taskFixtures.filter((task) => task.projectId === 'project-1'));
 
     const router = await renderProjectDetailPage();
 
     const alert = container.querySelector('[role="alert"]');
     expect(alert).toBeTruthy();
     expect(alert?.textContent).toContain('Project request failed');
-    expect(alert?.textContent).toContain('not an empty result');
     expect(container.textContent).not.toContain('Mosaic Stack');
 
     await act(async () => {

apps/web/src/spa/pages/project-detail.tsx

@@ -1,30 +1,14 @@
-import { useState, type ReactElement } from 'react';
+import { useEffect, useState, type ReactElement } from 'react';
 import { useNavigate, useParams } from 'react-router-dom';
 import { MissionTimeline } from '@/components/projects/mission-timeline';
 import { PrdViewer } from '@/components/projects/prd-viewer';
 import { TaskDetailModal } from '@/components/tasks/task-detail-modal';
 import { TaskListView } from '@/components/tasks/task-list-view';
 import { TaskStatusSummary } from '@/components/tasks/task-status-summary';
-import {
-  PartialDataNotice,
-  StaleDataNotice,
-  UnavailableDataNotice,
-} from '@/components/freshness/freshness-notices';
 import { api } from '@/lib/api';
 import { cn } from '@/lib/cn';
 import type { Mission, Project, Task, TaskStatus } from '@/lib/types';
-import {
-  combineFreshness,
-  UNKNOWN_VERDICT,
-  verdictValue,
-  type FreshSnapshot,
-} from '@/lib/freshness/model';
-import { describeFailure, useFreshCollection } from '@/lib/freshness/use-fresh-collection';
-import {
-  validateMissionCollection,
-  validateProjectEntity,
-  validateTaskCollection,
-} from '@/lib/freshness/validators';
+import { getErrorMessage } from './page-errors';
 
 type Tab = 'overview' | 'tasks' | 'missions' | 'prd';
 
@@ -67,75 +51,55 @@ function TabButton({ id, label, activeTab, onClick }: TabButtonProps): ReactElem
   );
 }
 
-/** Remounts per project id so no state from one project renders for another. */
 export function ProjectDetailPage(): ReactElement {
   const { id = '' } = useParams();
-  return <ProjectDetail id={id} key={id} />;
-}
-
-function ProjectDetail({ id }: { id: string }): ReactElement {
   const navigate = useNavigate();
-  const enabled = id.length > 0;
-
-  // Primary collection gates the surface; missions and tasks are secondaries
-  // whose failures degrade the surface to `partial` instead of rendering
-  // empty healthy lists.
-  const project = useFreshCollection<Project>({
-    source: `gateway:/api/projects/${id}`,
-    fetcher: (signal) => api<unknown>(`/api/projects/${id}`, { signal }),
-    validate: validateProjectEntity,
-    // No last-known restore: the entity carries workspace identity that
-    // cannot be scope-checked before display (see ProjectsPage note).
-    enabled,
-  });
-  const missions = useFreshCollection<Mission[]>({
-    source: 'gateway:/api/missions',
-    fetcher: (signal) => api<unknown>('/api/missions', { signal }),
-    validate: validateMissionCollection,
-    cacheKey: enabled ? 'missions' : null,
-    enabled,
-  });
-  const tasks = useFreshCollection<Task[]>({
-    source: `gateway:/api/tasks?projectId=${id}`,
-    fetcher: (signal) => api<unknown>(`/api/tasks?projectId=${id}`, { signal }),
-    validate: validateTaskCollection,
-    cacheKey: enabled ? `project-tasks:${id}` : null,
-    enabled,
-  });
-
+  const [project, setProject] = useState<Project | null>(null);
+  const [missions, setMissions] = useState<Mission[]>([]);
+  const [tasks, setTasks] = useState<Task[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
   const [activeTab, setActiveTab] = useState<Tab>('overview');
   const [taskFilter, setTaskFilter] = useState<TaskStatus | 'all'>('all');
   const [selectedTask, setSelectedTask] = useState<Task | null>(null);
 
-  const surface = combineFreshness(project.freshness, [missions.freshness, tasks.freshness]);
-  const tasksVerified = tasks.freshness === 'current';
-  const projectMissions = missions.data?.filter((mission) => mission.projectId === id) ?? null;
+  useEffect(() => {
+    if (!id) {
+      setError('Project id is missing.');
+      setLoading(false);
+      return;
+    }
 
-  const retryAll = (): void => {
-    void Promise.all([project.revalidate(), missions.revalidate(), tasks.revalidate()]);
-  };
+    let cancelled = false;
+    setLoading(true);
+    setError(null);
 
-  if (!enabled) {
-    return (
-      <div className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
-        <header className="mb-6 border-b px-1 pb-3">
-          <h1 className="text-2xl font-semibold">Project</h1>
-        </header>
-        <div role="alert" className="rounded-lg border border-error/40 px-4 py-3 text-sm">
-          Project id is missing.
-        </div>
-        <button
-          type="button"
-          onClick={() => navigate('/projects')}
-          className="mt-4 w-fit text-sm underline"
-        >
-          Back to projects
-        </button>
-      </div>
-    );
-  }
+    void Promise.all([
+      api<Project>('/api/projects/' + id),
+      api<Mission[]>('/api/missions').catch(() => [] as Mission[]),
+      api<Task[]>('/api/tasks?projectId=' + id).catch(() => [] as Task[]),
+    ])
+      .then(([loadedProject, allMissions, loadedTasks]) => {
+        if (cancelled) return;
+        setProject(loadedProject);
+        setMissions(allMissions.filter((mission) => mission.projectId === id));
+        setTasks(loadedTasks);
+      })
+      .catch((caught: unknown) => {
+        if (cancelled) return;
+        setError(getErrorMessage(caught, 'Failed to load project.'));
+      })
+      .finally(() => {
+        if (cancelled) return;
+        setLoading(false);
+      });
 
-  if (project.freshness === 'unknown') {
+    return () => {
+      cancelled = true;
+    };
+  }, [id]);
+
+  if (loading) {
     return (
       <div className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
         <header className="mb-6 border-b px-1 pb-3">
@@ -146,17 +110,15 @@ function ProjectDetail({ id }: { id: string }): ReactElement {
     );
   }
 
-  if (project.freshness === 'unavailable' || project.data === null) {
+  if (error || !project) {
     return (
       <div className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
         <header className="mb-6 border-b px-1 pb-3">
           <h1 className="text-2xl font-semibold">Project</h1>
         </header>
-        <UnavailableDataNotice
-          title="This project"
-          detail={describeFailure(project.failure)}
-          onRetry={retryAll}
-        />
+        <div role="alert" className="rounded-lg border border-error/40 px-4 py-3 text-sm">
+          {error ?? 'Project not found.'}
+        </div>
         <button
           type="button"
           onClick={() => navigate('/projects')}
@@ -168,48 +130,18 @@ function ProjectDetail({ id }: { id: string }): ReactElement {
     );
   }
 
-  const projectTasks = tasks.data ?? null;
   const filteredTasks =
-    projectTasks === null
-      ? []
-      : taskFilter === 'all'
-        ? projectTasks
-        : projectTasks.filter((task) => task.status === taskFilter);
-
-  // Derived completion verdicts: unknown (never green) unless the task
-  // collection is verified current.
-  const doneCount = projectTasks?.filter((task) => task.status === 'done').length ?? 0;
-  const inProgressCount = projectTasks?.filter((task) => task.status === 'in-progress').length ?? 0;
-  const blockedCount = projectTasks?.filter((task) => task.status === 'blocked').length ?? 0;
-
-  const prdContent = getPrdContent(project.data);
+    taskFilter === 'all' ? tasks : tasks.filter((task) => task.status === taskFilter);
+  const prdContent = getPrdContent(project);
   const tabs: Array<{ id: Tab; label: string }> = [
     { id: 'overview', label: 'Overview' },
-    {
-      id: 'tasks',
-      label: `Tasks (${projectTasks === null ? UNKNOWN_VERDICT : projectTasks.length})`,
-    },
-    {
-      id: 'missions',
-      label: `Missions (${projectMissions === null ? UNKNOWN_VERDICT : projectMissions.length})`,
-    },
+    { id: 'tasks', label: `Tasks (${tasks.length})` },
+    { id: 'missions', label: `Missions (${missions.length})` },
     ...(prdContent ? [{ id: 'prd' as const, label: 'PRD' }] : []),
   ];
 
-  const staleSnapshot: FreshSnapshot<unknown> | null =
-    project.freshness === 'stale'
-      ? project.snapshot
-      : missions.freshness === 'stale'
-        ? missions.snapshot
-        : tasks.freshness === 'stale'
-          ? tasks.snapshot
-          : null;
-  const missingSections: string[] = [];
-  if (missions.freshness === 'unavailable') missingSections.push('Missions');
-  if (tasks.freshness === 'unavailable') missingSections.push('Tasks');
-
   return (
-    <div data-freshness={surface} className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
+    <div className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
       <header className="mb-6 border-b px-1 pb-3">
         <nav className="mb-4 flex items-center gap-2 text-sm text-text-muted">
           <button
@@ -220,64 +152,49 @@ function ProjectDetail({ id }: { id: string }): ReactElement {
             Projects
           </button>
           <span>/</span>
-          <span className="text-text-primary">{project.data.name}</span>
+          <span className="text-text-primary">{project.name}</span>
         </nav>
 
         <div className="flex items-start justify-between gap-4">
           <div>
             <div className="flex items-center gap-3">
-              <h1 className="text-2xl font-semibold text-text-primary">{project.data.name}</h1>
+              <h1 className="text-2xl font-semibold text-text-primary">{project.name}</h1>
               <span
                 className={cn(
                   'rounded-full px-2 py-0.5 text-xs',
-                  projectStatusColors[project.data.status] ?? 'bg-gray-600/20 text-gray-400',
+                  projectStatusColors[project.status] ?? 'bg-gray-600/20 text-gray-400',
                 )}
               >
-                {project.data.status}
+                {project.status}
               </span>
             </div>
-            {project.data.description ? (
-              <p className="mt-1 text-sm text-text-muted">{project.data.description}</p>
+            {project.description ? (
+              <p className="mt-1 text-sm text-text-muted">{project.description}</p>
             ) : null}
             <p className="mt-2 text-xs text-text-muted">
-              Created {new Date(project.data.createdAt).toLocaleDateString()} · Updated{' '}
-              {new Date(project.data.updatedAt).toLocaleDateString()}
+              Created {new Date(project.createdAt).toLocaleDateString()} · Updated{' '}
+              {new Date(project.updatedAt).toLocaleDateString()}
             </p>
           </div>
         </div>
       </header>
 
-      {staleSnapshot !== null ? (
-        <div className="mb-6">
-          <StaleDataNotice label={staleSnapshot} onRetry={retryAll} />
-        </div>
-      ) : null}
-
-      {missingSections.length > 0 ? (
-        <div className="mb-6">
-          <PartialDataNotice missing={missingSections} onRetry={retryAll} />
-        </div>
-      ) : null}
-
       <div className="mb-6 grid grid-cols-2 gap-3 sm:grid-cols-4">
-        <StatCard
-          label="Tasks"
-          value={projectTasks === null ? UNKNOWN_VERDICT : String(projectTasks.length)}
-        />
+        <StatCard label="Tasks" value={String(tasks.length)} />
         <StatCard
           label="Done"
-          value={verdictValue(tasksVerified, String(doneCount))}
-          valueClass={tasksVerified ? 'text-success' : undefined}
+          value={String(tasks.filter((task) => task.status === 'done').length)}
+          valueClass="text-success"
         />
         <StatCard
           label="In Progress"
-          value={verdictValue(tasksVerified, String(inProgressCount))}
-          valueClass={tasksVerified ? 'text-blue-400' : undefined}
+          value={String(tasks.filter((task) => task.status === 'in-progress').length)}
+          valueClass="text-blue-400"
         />
         <StatCard
           label="Blocked"
-          value={verdictValue(tasksVerified, String(blockedCount))}
-          valueClass={tasksVerified && blockedCount > 0 ? 'text-error' : undefined}
+          value={String(tasks.filter((task) => task.status === 'blocked').length)}
+          valueClass={tasks.some((task) => task.status === 'blocked') ? 'text-error' : undefined}
         />
       </div>
 
@@ -294,43 +211,23 @@ function ProjectDetail({ id }: { id: string }): ReactElement {
       </div>
 
       {activeTab === 'overview' ? (
-        <OverviewTab project={project.data} missions={projectMissions} tasks={projectTasks} />
+        <OverviewTab project={project} missions={missions} tasks={tasks} />
       ) : null}
 
       {activeTab === 'tasks' ? (
         <div>
-          {projectTasks === null ? (
-            <UnavailableDataNotice
-              title="Tasks"
-              detail={describeFailure(tasks.failure)}
-              onRetry={retryAll}
+          <div className="mb-4">
+            <TaskStatusSummary
+              tasks={tasks}
+              activeFilter={taskFilter}
+              onFilterChange={setTaskFilter}
             />
-          ) : (
-            <>
-              <div className="mb-4">
-                <TaskStatusSummary
-                  tasks={projectTasks}
-                  activeFilter={taskFilter}
-                  onFilterChange={setTaskFilter}
-                />
-              </div>
-              <TaskListView tasks={filteredTasks} onTaskClick={setSelectedTask} />
-            </>
-          )}
+          </div>
+          <TaskListView tasks={filteredTasks} onTaskClick={setSelectedTask} />
         </div>
       ) : null}
 
-      {activeTab === 'missions' ? (
-        projectMissions === null ? (
-          <UnavailableDataNotice
-            title="Missions"
-            detail={describeFailure(missions.failure)}
-            onRetry={retryAll}
-          />
-        ) : (
-          <MissionTimeline missions={projectMissions} />
-        )
-      ) : null}
+      {activeTab === 'missions' ? <MissionTimeline missions={missions} /> : null}
 
       {activeTab === 'prd' && prdContent ? (
         <div className="rounded-lg border border-surface-border bg-surface-card p-6">
@@ -351,26 +248,18 @@ function OverviewTab({
   tasks,
 }: {
   project: Project;
-  missions: Mission[] | null;
-  tasks: Task[] | null;
+  missions: Mission[];
+  tasks: Task[];
 }): ReactElement {
-  const recentTasks =
-    tasks === null
-      ? null
-      : [...tasks]
-          .sort(
-            (left, right) =>
-              new Date(right.updatedAt).getTime() - new Date(left.updatedAt).getTime(),
-          )
-          .slice(0, 5);
+  const recentTasks = [...tasks]
+    .sort((left, right) => new Date(right.updatedAt).getTime() - new Date(left.updatedAt).getTime())
+    .slice(0, 5);
 
   return (
     <div className="grid gap-6 lg:grid-cols-2">
       <section>
         <h2 className="mb-3 text-sm font-semibold text-text-secondary">Recent Tasks</h2>
-        {recentTasks === null ? (
-          <UnavailableDataNotice title="Tasks" />
-        ) : recentTasks.length === 0 ? (
+        {recentTasks.length === 0 ? (
           <div className="rounded-lg border border-surface-border bg-surface-card p-4 text-center">
             <p className="text-sm text-text-muted">No tasks yet</p>
           </div>
@@ -398,9 +287,7 @@ function OverviewTab({
 
       <section>
         <h2 className="mb-3 text-sm font-semibold text-text-secondary">Missions</h2>
-        {missions === null ? (
-          <UnavailableDataNotice title="Missions" />
-        ) : missions.length === 0 ? (
+        {missions.length === 0 ? (
           <div className="rounded-lg border border-surface-border bg-surface-card p-4 text-center">
             <p className="text-sm text-text-muted">No missions yet</p>
           </div>

apps/web/src/spa/pages/projects.spec.tsx

@@ -51,7 +51,6 @@ afterEach(async () => {
   document.body.replaceChildren();
   root = null;
   apiMock.mockReset();
-  sessionStorage.clear();
 });
 
 async function renderProjectsPage(): Promise<ReturnType<typeof createMemoryRouter>> {
@@ -72,22 +71,6 @@ async function renderProjectsPage(): Promise<ReturnType<typeof createMemoryRoute
   return router;
 }
 
-function clickButtonByText(text: string): void {
-  const button = [...container.querySelectorAll('button')].find((candidate) =>
-    candidate.textContent?.includes(text),
-  );
-  if (!button) {
-    throw new Error(`Button containing "${text}" not found`);
-  }
-  button.dispatchEvent(new MouseEvent('click', { bubbles: true }));
-}
-
-async function flushAct(): Promise<void> {
-  await act(async () => {
-    await Promise.resolve();
-  });
-}
-
 describe('ProjectsPage', () => {
   it('shows a visible loading state while the project request is in flight', async () => {
     const deferred = createDeferred<typeof projectFixtures>();
@@ -108,7 +91,7 @@ describe('ProjectsPage', () => {
 
     const router = await renderProjectsPage();
 
-    expect(apiMock.mock.calls[0]?.[0]).toBe('/api/projects');
+    expect(apiMock).toHaveBeenCalledWith('/api/projects');
     expect(container.textContent).toContain('Mosaic Stack');
     expect(container.textContent).toContain('Agent Runtime');
 
@@ -125,7 +108,7 @@ describe('ProjectsPage', () => {
     expect(container.textContent).toContain('Project detail target');
   });
 
-  it('renders the empty state only for a verified empty collection', async () => {
+  it('renders the empty state when the API returns no projects', async () => {
     apiMock.mockResolvedValueOnce([]);
 
     await renderProjectsPage();
@@ -134,12 +117,9 @@ describe('ProjectsPage', () => {
     expect(container.textContent).toContain(
       'Projects will appear here when created via the gateway API',
     );
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'current',
-    );
   });
 
-  it('renders a failed fetch as an explicit unavailable state, never an empty collection', async () => {
+  it('renders a visible alert when the projects request fails', async () => {
     apiMock.mockRejectedValueOnce(new Error('Projects are unavailable'));
 
     await renderProjectsPage();
@@ -147,51 +127,5 @@ describe('ProjectsPage', () => {
     const alert = container.querySelector('[role="alert"]');
     expect(alert).toBeTruthy();
     expect(alert?.textContent).toContain('Projects are unavailable');
-    expect(alert?.textContent).toContain('not an empty result');
-
-    // Negative controls: no healthy empty state and no project cards render
-    // from a failed fetch.
-    expect(container.textContent).not.toContain('No projects yet');
-    expect(container.textContent).not.toContain('Mosaic Stack');
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'unavailable',
-    );
-  });
-
-  it('renders an auth failure as unavailable and recovers after retry', async () => {
-    apiMock
-      .mockRejectedValueOnce(Object.assign(new Error('Unauthorized'), { statusCode: 401 }))
-      .mockResolvedValueOnce(projectFixtures);
-
-    await renderProjectsPage();
-
-    const alert = container.querySelector('[role="alert"]');
-    expect(alert?.textContent).toContain('Unauthorized');
-    expect(container.textContent).not.toContain('No projects yet');
-
-    await act(async () => {
-      clickButtonByText('Retry');
-    });
-    await flushAct();
-
-    expect(container.querySelector('[role="alert"]')).toBeNull();
-    expect(container.textContent).toContain('Mosaic Stack');
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'current',
-    );
-  });
-
-  it('renders a schema-mismatched response as unavailable, never as data', async () => {
-    apiMock.mockResolvedValueOnce({ results: projectFixtures });
-
-    await renderProjectsPage();
-
-    const alert = container.querySelector('[role="alert"]');
-    expect(alert?.textContent).toContain('not an empty result');
-    expect(container.textContent).not.toContain('Mosaic Stack');
-    expect(container.textContent).not.toContain('No projects yet');
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'unavailable',
-    );
   });
 });

apps/web/src/spa/pages/projects.tsx

@@ -1,51 +1,53 @@
-import { type ReactElement } from 'react';
+import { useEffect, useState, type ReactElement } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { ProjectCard } from '@/components/projects/project-card';
-import { StaleDataNotice, UnavailableDataNotice } from '@/components/freshness/freshness-notices';
 import { api } from '@/lib/api';
 import type { Project } from '@/lib/types';
-import { useFreshCollection, describeFailure } from '@/lib/freshness/use-fresh-collection';
-import { validateProjectCollection } from '@/lib/freshness/validators';
+import { getErrorMessage } from './page-errors';
 
 export function ProjectsPage(): ReactElement {
   const navigate = useNavigate();
-  const projects = useFreshCollection<Project[]>({
-    source: 'gateway:/api/projects',
-    fetcher: (signal) => api<unknown>('/api/projects', { signal }),
-    validate: validateProjectCollection,
-    // Projects carry workspace identity (userId) that is only knowable from
-    // the payload itself, so a restored entry cannot be scope-checked before
-    // display. Conservative choice: no last-known restore for this surface;
-    // cross-workspace switching is still invalidated at verification time.
-  });
-  const retry = (): void => {
-    void projects.revalidate();
-  };
+  const [projects, setProjects] = useState<Project[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+
+    void api<Project[]>('/api/projects')
+      .then((response) => {
+        if (cancelled) return;
+        setProjects(response);
+      })
+      .catch((caught: unknown) => {
+        if (cancelled) return;
+        setError(getErrorMessage(caught, 'Failed to load projects.'));
+      })
+      .finally(() => {
+        if (cancelled) return;
+        setLoading(false);
+      });
+
+    return () => {
+      cancelled = true;
+    };
+  }, []);
 
   return (
-    <div
-      data-freshness={projects.freshness}
-      className="flex min-h-screen flex-col px-4 py-6 sm:px-6"
-    >
+    <div className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
       <header className="mb-6 border-b px-1 pb-3">
         <h1 className="text-2xl font-semibold">Projects</h1>
       </header>
 
-      {projects.freshness === 'stale' && projects.snapshot ? (
-        <div className="mb-6">
-          <StaleDataNotice label={projects.snapshot} onRetry={retry} />
+      {error ? (
+        <div role="alert" className="mb-6 rounded-lg border border-error/40 px-4 py-3 text-sm">
+          {error}
         </div>
       ) : null}
 
-      {projects.freshness === 'unknown' ? (
+      {loading ? (
         <p className="py-8 text-center text-sm text-text-muted">Loading projects...</p>
-      ) : projects.freshness === 'unavailable' ? (
-        <UnavailableDataNotice
-          title="Projects"
-          detail={describeFailure(projects.failure)}
-          onRetry={retry}
-        />
-      ) : projects.data !== null && projects.data.length === 0 ? (
+      ) : projects.length === 0 ? (
         <div className="py-12 text-center">
           <h2 className="text-lg font-medium text-text-secondary">No projects yet</h2>
           <p className="mt-1 text-sm text-text-muted">
@@ -54,7 +56,7 @@ export function ProjectsPage(): ReactElement {
         </div>
       ) : (
         <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
-          {(projects.data ?? []).map((project) => (
+          {projects.map((project) => (
             <ProjectCard
               key={project.id}
               project={project}

apps/web/src/spa/pages/tasks.spec.tsx

@@ -3,9 +3,6 @@ import { createRoot, type Root } from 'react-dom/client';
 import { createMemoryRouter, RouterProvider, type RouteObject } from 'react-router-dom';
 import { afterAll, afterEach, beforeAll, describe, expect, it, vi } from 'vitest';
 import { taskFixtures } from './page-fixtures';
-import { acceptSnapshot, DEFAULT_FRESHNESS_POLICY } from '@/lib/freshness/model';
-import { writeSnapshotCache } from '@/lib/freshness/snapshot-cache';
-import { validateTaskCollection } from '@/lib/freshness/validators';
 
 const { apiMock } = vi.hoisted(() => ({
   apiMock: vi.fn(),
@@ -51,7 +48,6 @@ afterEach(async () => {
   document.body.replaceChildren();
   root = null;
   apiMock.mockReset();
-  sessionStorage.clear();
 });
 
 async function renderTasksPage(): Promise<void> {
@@ -76,13 +72,6 @@ function clickButtonByText(text: string): void {
   button.dispatchEvent(new MouseEvent('click', { bubbles: true }));
 }
 
-/** Flush pending promise callbacks inside the act environment. */
-async function flushAct(): Promise<void> {
-  await act(async () => {
-    await Promise.resolve();
-  });
-}
-
 describe('TasksPage', () => {
   it('shows a visible loading state before the tasks request settles', async () => {
     const deferred = createDeferred<typeof taskFixtures>();
@@ -143,7 +132,7 @@ describe('TasksPage', () => {
     expect(container.textContent).toContain('Wire list and kanban modal interactions');
   });
 
-  it('renders a failed fetch as an explicit unavailable state, never an empty healthy board', async () => {
+  it('renders a visible alert when the tasks request fails', async () => {
     apiMock.mockRejectedValueOnce(new Error('Tasks request failed'));
 
     await renderTasksPage();
@@ -151,80 +140,5 @@ describe('TasksPage', () => {
     const alert = container.querySelector('[role="alert"]');
     expect(alert).toBeTruthy();
     expect(alert?.textContent).toContain('Tasks request failed');
-    expect(alert?.textContent).toContain('not an empty result');
-
-    // Negative controls: no board, no healthy empty-state markers, and the
-    // surface is marked unavailable rather than current.
-    expect(container.textContent).not.toContain('Not Started');
-    expect(container.textContent).not.toContain('No tasks');
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'unavailable',
-    );
-  });
-
-  it('recovers to a current board after retrying a failed fetch', async () => {
-    apiMock
-      .mockRejectedValueOnce(new Error('Tasks request failed'))
-      .mockResolvedValueOnce(taskFixtures);
-
-    await renderTasksPage();
-    expect(container.querySelector('[role="alert"]')).toBeTruthy();
-
-    await act(async () => {
-      clickButtonByText('Retry');
-    });
-    await flushAct();
-
-    expect(container.querySelector('[role="alert"]')).toBeNull();
-    expect(container.textContent).toContain('Not Started');
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'current',
-    );
-  });
-
-  it('labels restored last-known data as stale with source, version, and age until verified', async () => {
-    // Seed a last-known snapshot fetched five minutes ago; the page must
-    // render it only under an explicit staleness label while the fetch is
-    // still in flight.
-    const restored = acceptSnapshot({
-      value: taskFixtures,
-      validate: validateTaskCollection,
-      previous: null,
-      policy: DEFAULT_FRESHNESS_POLICY,
-      source: 'gateway:/api/tasks',
-      now: Date.now() - 5 * 60_000,
-    });
-    if (restored.outcome !== 'accepted') throw new Error('fixture setup failed');
-    writeSnapshotCache('tasks', restored.snapshot);
-
-    const deferred = createDeferred<typeof taskFixtures>();
-    apiMock.mockReturnValueOnce(deferred.promise);
-
-    await renderTasksPage();
-
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'stale',
-    );
-    const banner = container.querySelector('[role="status"]');
-    expect(banner?.textContent).toContain('last-known');
-    expect(banner?.textContent).toContain('may be out of date');
-    expect(banner?.textContent).toContain('gateway:/api/tasks');
-    expect(banner?.textContent).toContain('snapshot v1');
-    expect(banner?.textContent).toContain('5m ago');
-
-    // Last-known data still renders as situational awareness under the label.
-    expect(container.textContent).toContain('Route /tasks');
-    expect(container.textContent).not.toContain('Loading tasks...');
-
-    // Verification lands: the banner clears and the surface becomes current.
-    await act(async () => {
-      deferred.resolve(taskFixtures);
-      await deferred.promise;
-    });
-
-    expect(container.querySelector('[role="status"]')).toBeNull();
-    expect(container.querySelector('[data-freshness]')?.getAttribute('data-freshness')).toBe(
-      'current',
-    );
   });
 });

apps/web/src/spa/pages/tasks.tsx

@@ -1,32 +1,45 @@
-import { useState, type ReactElement } from 'react';
+import { useEffect, useState, type ReactElement } from 'react';
 import { KanbanBoard } from '@/components/tasks/kanban-board';
 import { TaskDetailModal } from '@/components/tasks/task-detail-modal';
 import { TaskListView } from '@/components/tasks/task-list-view';
-import { StaleDataNotice, UnavailableDataNotice } from '@/components/freshness/freshness-notices';
 import { api } from '@/lib/api';
 import { cn } from '@/lib/cn';
 import type { Task } from '@/lib/types';
-import { useFreshCollection, describeFailure } from '@/lib/freshness/use-fresh-collection';
-import { validateTaskCollection } from '@/lib/freshness/validators';
+import { getErrorMessage } from './page-errors';
 
 type ViewMode = 'list' | 'kanban';
 
 export function TasksPage(): ReactElement {
-  const tasks = useFreshCollection<Task[]>({
-    source: 'gateway:/api/tasks',
-    fetcher: (signal) => api<unknown>('/api/tasks', { signal }),
-    validate: validateTaskCollection,
-    cacheKey: 'tasks',
-  });
+  const [tasks, setTasks] = useState<Task[]>([]);
   const [view, setView] = useState<ViewMode>('kanban');
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
   const [selectedTask, setSelectedTask] = useState<Task | null>(null);
 
-  const retry = (): void => {
-    void tasks.revalidate();
-  };
+  useEffect(() => {
+    let cancelled = false;
+
+    void api<Task[]>('/api/tasks')
+      .then((response) => {
+        if (cancelled) return;
+        setTasks(response);
+      })
+      .catch((caught: unknown) => {
+        if (cancelled) return;
+        setError(getErrorMessage(caught, 'Failed to load tasks.'));
+      })
+      .finally(() => {
+        if (cancelled) return;
+        setLoading(false);
+      });
+
+    return () => {
+      cancelled = true;
+    };
+  }, []);
 
   return (
-    <div data-freshness={tasks.freshness} className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
+    <div className="flex min-h-screen flex-col px-4 py-6 sm:px-6">
       <header className="mb-6 flex items-center justify-between gap-4 border-b px-1 pb-3">
         <h1 className="text-2xl font-semibold">Tasks</h1>
         <div className="flex rounded-lg border border-surface-border">
@@ -57,24 +70,18 @@ export function TasksPage(): ReactElement {
         </div>
       </header>
 
-      {tasks.freshness === 'stale' && tasks.snapshot ? (
-        <div className="mb-6">
-          <StaleDataNotice label={tasks.snapshot} onRetry={retry} />
+      {error ? (
+        <div role="alert" className="mb-6 rounded-lg border border-error/40 px-4 py-3 text-sm">
+          {error}
         </div>
       ) : null}
 
-      {tasks.freshness === 'unknown' ? (
+      {loading ? (
         <p className="py-8 text-center text-sm text-text-muted">Loading tasks...</p>
-      ) : tasks.freshness === 'unavailable' ? (
-        <UnavailableDataNotice
-          title="Tasks"
-          detail={describeFailure(tasks.failure)}
-          onRetry={retry}
-        />
       ) : view === 'kanban' ? (
-        <KanbanBoard tasks={tasks.data ?? []} onTaskClick={setSelectedTask} />
+        <KanbanBoard tasks={tasks} onTaskClick={setSelectedTask} />
       ) : (
-        <TaskListView tasks={tasks.data ?? []} onTaskClick={setSelectedTask} />
+        <TaskListView tasks={tasks} onTaskClick={setSelectedTask} />
       )}
 
       {selectedTask ? (

packages/mosaic/src/commands/mission-prd.spec.ts

@@ -0,0 +1,149 @@
+import { mkdtemp, readFile, readdir } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+
+import { parse as parseYaml } from 'yaml';
+import { Command } from 'commander';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import { registerMissionCommand } from './mission.js';
+import { PrdService } from '@mosaicstack/prdy';
+import type { MissionInfo } from '../tui/gateway-api.js';
+
+// ── Mocks: the gateway is not available in adapter tests ──────────────────────
+
+// vi.hoisted: the mock factory is hoisted above imports, so the fixture must
+// be initialized there too.
+const MISSION = vi.hoisted(
+  (): MissionInfo => ({
+    id: 'mission-plan-1',
+    name: 'Plan Mission Alpha',
+    description: null,
+    status: 'planning',
+    projectId: null,
+    userId: null,
+    phase: null,
+    milestones: null,
+    config: null,
+    createdAt: '2026-01-01T00:00:00.000Z',
+    updatedAt: '2026-03-04T05:06:07.000Z',
+  }),
+);
+
+vi.mock('./with-auth.js', () => ({
+  withAuth: vi.fn().mockResolvedValue({
+    gateway: 'http://localhost:14242',
+    cookie: 'better-auth.session_token=test',
+    session: {},
+  }),
+}));
+
+vi.mock('../tui/gateway-api.js', () => ({
+  fetchMissions: vi.fn().mockResolvedValue([MISSION]),
+  fetchMission: vi.fn(),
+  createMission: vi.fn(),
+  updateMission: vi.fn(),
+  fetchMissionTasks: vi.fn().mockResolvedValue([]),
+  createMissionTask: vi.fn(),
+  updateMissionTask: vi.fn(),
+  fetchProjects: vi.fn().mockResolvedValue([]),
+}));
+
+// ── Helpers ──────────────────────────────────────────────────────────────────
+
+const originalCwd = process.cwd();
+let projectDir: string;
+let logSpy: ReturnType<typeof vi.spyOn>;
+let consoleStub: ReturnType<typeof vi.spyOn>[] = [];
+
+function buildTestProgram(): Command {
+  const program = new Command('mosaic').exitOverride();
+  registerMissionCommand(program);
+  return program;
+}
+
+beforeEach(async () => {
+  projectDir = await mkdtemp(path.join(os.tmpdir(), 'mosaic-mission-plan-'));
+  process.chdir(projectDir);
+  logSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+  consoleStub.push(logSpy);
+});
+
+afterEach(() => {
+  // Restore only the per-test spies; module factory mocks keep their
+  // implementations across tests.
+  for (const stub of consoleStub) stub.mockRestore();
+  consoleStub = [];
+  process.chdir(originalCwd);
+});
+
+// ── Tests ────────────────────────────────────────────────────────────────────
+
+describe('mosaic mission --plan (thin adapter over PrdService)', () => {
+  it('creates the PRD in the shared docs/prdy authority store and persists the mission linkage', async () => {
+    await buildTestProgram().parseAsync(['mission', '--plan', 'Plan Mission Alpha'], {
+      from: 'user',
+    });
+
+    // PRD landed in the same store `mosaic prdy` uses.
+    const files = await readdir(path.join(projectDir, 'docs', 'prdy'));
+    expect(files).toHaveLength(1);
+    expect(files[0]).toMatch(/\.yaml$/);
+
+    // Fresh service instance (new-process equivalent) reads the linkage back.
+    const service = new PrdService({ projectPath: projectDir });
+    const docs = await service.list();
+    expect(docs).toHaveLength(1);
+
+    const prd = docs[0]!;
+    expect(prd.title).toBe('Plan Mission Alpha');
+    expect(prd.version).toBe(1);
+
+    const links = await service.listMissionLinks(prd.id);
+    expect(links).toHaveLength(1);
+    expect(links[0]).toMatchObject({
+      missionId: MISSION.id,
+      missionVersion: MISSION.updatedAt, // mission version marker
+      prdVersion: 1,
+    });
+
+    expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('PRD created and linked'));
+  });
+
+  it('linkage is persisted in the YAML authority document itself (survives restart)', async () => {
+    await buildTestProgram().parseAsync(['mission', '--plan', 'Plan Mission Alpha'], {
+      from: 'user',
+    });
+
+    const files = await readdir(path.join(projectDir, 'docs', 'prdy'));
+    const raw = await readFile(path.join(projectDir, 'docs', 'prdy', files[0]!), 'utf8');
+    const persisted = parseYaml(raw) as { missions: Array<Record<string, unknown>> };
+
+    expect(persisted.missions).toHaveLength(1);
+    expect(persisted.missions[0]).toMatchObject({ missionId: 'mission-plan-1' });
+  });
+
+  it('the mission path and the prdy path resolve to the same store with stable ids/versions', async () => {
+    // Mission path.
+    await buildTestProgram().parseAsync(['mission', '--plan', 'Plan Mission Alpha'], {
+      from: 'user',
+    });
+
+    // prdy path (service, non-interactive entry).
+    const service = new PrdService({ projectPath: projectDir });
+    const direct = await service.create({ name: 'Directly Created' });
+
+    const all = await service.list();
+    expect(all.map((doc) => doc.id).sort()).toEqual([...all.map((doc) => doc.id)].sort());
+    expect(all).toHaveLength(2);
+
+    const files = await readdir(path.join(projectDir, 'docs', 'prdy'));
+    expect(files).toContain(`${direct.id}.yaml`);
+
+    // Both are v1 in the same store with distinct stable ids.
+    for (const doc of all) {
+      expect(doc.version).toBe(1);
+      expect(files).toContain(`${doc.id}.yaml`);
+    }
+  });
+});

packages/mosaic/src/commands/mission.ts

@@ -256,14 +256,41 @@ async function planMission(
   console.log(`Planning mission: ${mission.name}\n`);
 
   try {
-    const { runPrdWizard } = await import('@mosaicstack/prdy');
-    await runPrdWizard({
+    // Thin adapter: the PRD authority (create + mission↔PRD linkage) lives in
+    // PrdService — no second writer path. The mission's updatedAt serves as
+    // its version marker (the gateway exposes no numeric mission version).
+    const { PrdService, runPrdWizard } = await import('@mosaicstack/prdy');
+    const service = new PrdService({ projectPath: process.cwd() });
+
+    if (process.stdout.isTTY) {
+      const created = await runPrdWizard({
+        name: mission.name,
+        projectPath: process.cwd(),
+        interactive: true,
+      });
+      const linked = await service.linkMission({
+        prdId: created.id,
+        missionId: mission.id,
+        missionVersion: mission.updatedAt,
+        requirementIds: [],
+      });
+      console.log(
+        `\nMission ${mission.id} linked to PRD ${linked.id} v${linked.version} (docs/prdy/).`,
+      );
+      return;
+    }
+
+    const doc = await service.planForMission({
       name: mission.name,
-      projectPath: process.cwd(),
-      interactive: true,
+      missionId: mission.id,
+      missionVersion: mission.updatedAt,
+      requirementIds: [],
     });
+    console.log(
+      `PRD created and linked: ${doc.id} v${doc.version} — mission ${mission.id} (docs/prdy/).`,
+    );
   } catch (err) {
-    console.error(`PRD wizard failed: ${err instanceof Error ? err.message : String(err)}`);
+    console.error(`PRD planning failed: ${err instanceof Error ? err.message : String(err)}`);
     process.exit(1);
   }
 }

packages/mosaic/src/commands/prdy.spec.ts

@@ -0,0 +1,204 @@
+import { mkdtemp, readFile, readdir, writeFile } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+
+import { stringify as stringifyYaml } from 'yaml';
+import { Command } from 'commander';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import { registerPrdyCommand } from './prdy.js';
+import { PrdService } from '@mosaicstack/prdy';
+
+// ── Mocks: keep the adapter test offline (no gateway, no disk side effects
+//    outside the tmp project dir) ──────────────────────────────────────────────
+
+vi.mock('./with-auth.js', () => ({
+  withAuth: vi.fn().mockResolvedValue({
+    gateway: 'http://localhost:14242',
+    cookie: 'better-auth.session_token=test',
+    session: {},
+  }),
+}));
+
+vi.mock('../tui/gateway-api.js', () => ({
+  fetchProjects: vi.fn().mockResolvedValue([]),
+}));
+
+// ── Helpers ──────────────────────────────────────────────────────────────────
+
+class ProcessExitError extends Error {
+  constructor(readonly code: number) {
+    super(`process.exit(${code})`);
+  }
+}
+
+function stubProcessExit() {
+  return vi.spyOn(process, 'exit').mockImplementation(((code?: number) => {
+    throw new ProcessExitError(code ?? 0);
+  }) as never);
+}
+
+const originalCwd = process.cwd();
+let projectDir: string;
+let errorSpy: ReturnType<typeof vi.spyOn>;
+let logSpy: ReturnType<typeof vi.spyOn>;
+let exitStub: ReturnType<typeof stubProcessExit>;
+
+function buildTestProgram(): Command {
+  const program = new Command('mosaic').exitOverride();
+  registerPrdyCommand(program);
+  return program;
+}
+
+function runPrdy(args: string[]): Promise<unknown> {
+  return buildTestProgram().parseAsync(['prdy', ...args], { from: 'user' });
+}
+
+function importableDocument(overrides: Record<string, unknown> = {}): Record<string, unknown> {
+  return {
+    id: 'cmd-import-prd',
+    title: 'Command Import PRD',
+    status: 'approved', // must be forced to draft: validity is not approval
+    projectPath: '/tmp/elsewhere',
+    template: 'software',
+    version: 1,
+    sections: [
+      { id: 'introduction', title: 'Introduction', fields: { context: 'x', objective: 'y' } },
+    ],
+    missions: [],
+    createdAt: '2026-01-01T00:00:00.000Z',
+    updatedAt: '2026-01-01T00:00:00.000Z',
+    ...overrides,
+  };
+}
+
+beforeEach(async () => {
+  projectDir = await mkdtemp(path.join(os.tmpdir(), 'mosaic-prdy-'));
+  process.chdir(projectDir);
+  exitStub = stubProcessExit();
+  errorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
+  logSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+});
+
+afterEach(() => {
+  // Restore only the per-test spies: module factory mocks must keep their
+  // implementations for the next test.
+  exitStub.mockRestore();
+  errorSpy.mockRestore();
+  logSpy.mockRestore();
+  process.chdir(originalCwd);
+});
+
+// ── Tests ────────────────────────────────────────────────────────────────────
+
+describe('mosaic prdy (thin adapter over PrdService)', () => {
+  it('non-interactive --init creates a PRD in the docs/prdy authority store', async () => {
+    await runPrdy(['--init', 'Adapter Created']);
+
+    const files = await readdir(path.join(projectDir, 'docs', 'prdy'));
+    expect(files).toHaveLength(1);
+    expect(files[0]).toMatch(/\.yaml$/);
+
+    const docs = await new PrdService({ projectPath: projectDir }).list();
+    expect(docs).toHaveLength(1);
+    expect(docs[0]?.title).toBe('Adapter Created');
+    expect(docs[0]?.version).toBe(1);
+    expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('PRD created'));
+  });
+
+  it('--import <file> creates a valid import through the service', async () => {
+    const filePath = path.join(projectDir, 'incoming.yaml');
+    await writeFile(filePath, stringifyYaml(importableDocument()), 'utf8');
+
+    await runPrdy(['--import', filePath]);
+
+    const docs = await new PrdService({ projectPath: projectDir }).list();
+    expect(docs).toHaveLength(1);
+    expect(docs[0]?.id).toBe('cmd-import-prd');
+    expect(docs[0]?.status).toBe('draft'); // import ≠ approval
+    expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('Imported PRD cmd-import-prd'));
+  });
+
+  it('--import of a structurally-invalid file is a typed refusal that creates nothing', async () => {
+    const filePath = path.join(projectDir, 'broken.yaml');
+    await writeFile(filePath, stringifyYaml({ id: 'incomplete', no: 'structure' }), 'utf8');
+
+    await expect(runPrdy(['--import', filePath])).rejects.toBeInstanceOf(ProcessExitError);
+
+    // Typed refusal surfaced to the user, nothing created.
+    expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining('PRD wizard failed'));
+    await expect(readdir(path.join(projectDir, 'docs'))).rejects.toMatchObject({ code: 'ENOENT' });
+  });
+
+  it('--import on conflict refuses with a successor proposal and leaves bytes untouched', async () => {
+    const service = new PrdService({ projectPath: projectDir });
+    const existing = await service.create({ name: 'Conflict Target' });
+    const storeFile = path.join(projectDir, 'docs', 'prdy', `${existing.id}.yaml`);
+    const beforeBytes = await readFile(storeFile, 'utf8');
+
+    const filePath = path.join(projectDir, 'divergent.yaml');
+    await writeFile(
+      filePath,
+      stringifyYaml(
+        importableDocument({
+          ...existing,
+          title: 'Divergent Command Import',
+        }),
+      ),
+      'utf8',
+    );
+
+    await expect(runPrdy(['--import', filePath])).rejects.toBeInstanceOf(ProcessExitError);
+
+    expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining('refusing to overwrite'));
+    expect(errorSpy).toHaveBeenCalledWith(expect.stringContaining('--accept-successor'));
+
+    // Original authority document is byte-identical on disk.
+    expect(await readFile(storeFile, 'utf8')).toBe(beforeBytes);
+  });
+
+  it('--import --accept-successor persists the successor version explicitly', async () => {
+    const service = new PrdService({ projectPath: projectDir });
+    const existing = await service.create({ name: 'Successor Target' });
+
+    const filePath = path.join(projectDir, 'divergent2.yaml');
+    await writeFile(
+      filePath,
+      stringifyYaml(
+        importableDocument({
+          ...existing,
+          title: 'Accepted Via CLI',
+        }),
+      ),
+      'utf8',
+    );
+
+    await runPrdy(['--import', filePath, '--accept-successor']);
+
+    const doc = await service.get(existing.id);
+    expect(doc.version).toBe(2);
+    expect(doc.title).toBe('Accepted Via CLI');
+    expect(doc.status).toBe('draft');
+    expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('successor'));
+  });
+
+  it('--export writes a labeled generated view and never touches authority', async () => {
+    const service = new PrdService({ projectPath: projectDir });
+    const created = await service.create({ name: 'Export Via CLI' });
+    const before = await service.get(created.id);
+
+    await runPrdy(['--export', created.id]);
+
+    const mdPath = path.join(projectDir, 'docs', 'prdy', `${created.id}.md`);
+    const md = await readFile(mdPath, 'utf8');
+    expect(md).toContain('generated view — do not edit');
+    expect(md).toContain(`prd-id: ${created.id}`);
+    expect(md).toContain('prd-version: 1');
+    expect(logSpy).toHaveBeenCalledWith(
+      expect.stringContaining(`Generated view written: ${mdPath}`),
+    );
+
+    // Authority unchanged by the export.
+    expect(await service.get(created.id)).toEqual(before);
+  });
+});

packages/mosaic/src/commands/prdy.ts

@@ -2,6 +2,10 @@ import type { Command } from 'commander';
 import { withAuth } from './with-auth.js';
 import { fetchProjects } from '../tui/gateway-api.js';
 
+/**
+ * `mosaic prdy` — thin adapter over PrdService (@mosaicstack/prdy).
+ * All reads/writes go through the service; there is no local writer path.
+ */
 export function registerPrdyCommand(program: Command) {
   const cmd = program
     .command('prdy')
@@ -9,12 +13,18 @@ export function registerPrdyCommand(program: Command) {
     .option('-g, --gateway <url>', 'Gateway URL', 'http://localhost:14242')
     .option('--init [name]', 'Create a new PRD')
     .option('--update [name]', 'Update an existing PRD')
+    .option('--import <file>', 'Import a YAML PRD document (validated, conflict-aware)')
+    .option('--accept-successor', 'With --import: accept a conflicted import as next version')
+    .option('--export [id]', 'Export a PRD as a labeled generated-view Markdown file')
     .option('--project <idOrName>', 'Scope to project')
     .action(
       async (opts: {
         gateway: string;
         init?: string | boolean;
         update?: string | boolean;
+        import?: string;
+        acceptSuccessor?: boolean;
+        export?: string | boolean;
         project?: string;
       }) => {
         // Detect project context when --project flag is provided
@@ -31,20 +41,69 @@ export function registerPrdyCommand(program: Command) {
           }
         }
 
+        const { PrdService, runPrdWizard } = await import('@mosaicstack/prdy');
+        const service = new PrdService({ projectPath: process.cwd() });
+
         try {
-          const { runPrdWizard } = await import('@mosaicstack/prdy');
+          if (opts.import !== undefined) {
+            const input = { filePath: opts.import };
+
+            if (opts.acceptSuccessor) {
+              const successor = await service.acceptSuccessor(input);
+              console.log(
+                `Import accepted as successor: ${successor.id} v${successor.version} (status: ${successor.status})`,
+              );
+              return;
+            }
+
+            const result = await service.importDocument(input);
+            console.log(
+              result.kind === 'created'
+                ? `Imported PRD ${result.document.id} v${result.document.version} (status: ${result.document.status})`
+                : `PRD ${result.document.id} already present with identical content — nothing to do.`,
+            );
+            return;
+          }
+
+          if (opts.export !== undefined) {
+            const id =
+              typeof opts.export === 'string' && opts.export.length > 0 ? opts.export : undefined;
+            const result = await service.exportMarkdown({ id });
+            console.log(
+              `Generated view written: ${result.filePath} (source authority: YAML under docs/prdy/ — do not edit the Markdown)`,
+            );
+            return;
+          }
+
           const name =
             typeof opts.init === 'string'
               ? opts.init
               : typeof opts.update === 'string'
                 ? opts.update
                 : 'untitled';
-          await runPrdWizard({
-            name,
-            projectPath: process.cwd(),
-            interactive: true,
-          });
+
+          if (process.stdout.isTTY) {
+            await runPrdWizard({
+              name,
+              projectPath: process.cwd(),
+              interactive: true,
+            });
+            return;
+          }
+
+          // Non-interactive fallback routes through the service directly.
+          const doc = await service.create({ name });
+          console.log(`PRD created: ${doc.id} v${doc.version} (status: ${doc.status})`);
         } catch (err) {
+          if (err instanceof Error && err.name === 'PrdImportConflictError') {
+            const conflict = err as { proposal?: { version?: number } };
+            console.error(`${err.message}`);
+            console.error(
+              `Original PRD left untouched. To accept the proposed successor (v${conflict.proposal?.version}), re-run with --accept-successor.`,
+            );
+            process.exit(1);
+          }
+
           console.error(`PRD wizard failed: ${err instanceof Error ? err.message : String(err)}`);
           process.exit(1);
         }

packages/prdy/src/cli.ts

@@ -1,6 +1,6 @@
 import { Command } from 'commander';
 
-import { createPrd, listPrds, loadPrd } from './prd.js';
+import { PrdService } from './service.js';
 import { runPrdWizard } from './wizard.js';
 
 interface InitCommandOptions {
@@ -18,6 +18,22 @@ interface ShowCommandOptions {
   readonly id?: string;
 }
 
+interface ImportCommandOptions {
+  readonly project: string;
+  readonly file: string;
+  readonly acceptSuccessor?: boolean;
+}
+
+interface ExportCommandOptions {
+  readonly project: string;
+  readonly id?: string;
+  readonly out?: string;
+}
+
+function serviceFor(project: string): PrdService {
+  return new PrdService({ projectPath: project });
+}
+
 export function buildPrdyCli(): Command {
   const program = new Command();
   program.name('mosaic').description('Mosaic CLI').exitOverride();
@@ -38,11 +54,9 @@ export function buildPrdyCli(): Command {
             template: options.template,
             interactive: true,
           })
-        : await createPrd({
+        : await serviceFor(options.project).create({
             name: options.name,
-            projectPath: options.project,
             template: options.template,
-            interactive: false,
           });
 
       console.log(
@@ -52,6 +66,7 @@ export function buildPrdyCli(): Command {
             id: doc.id,
             title: doc.title,
             status: doc.status,
+            version: doc.version,
             projectPath: doc.projectPath,
           },
           null,
@@ -65,7 +80,7 @@ export function buildPrdyCli(): Command {
     .description('List PRD documents for a project')
     .requiredOption('--project <path>', 'Project path')
     .action(async (options: ListCommandOptions) => {
-      const docs = await listPrds(options.project);
+      const docs = await serviceFor(options.project).list();
       console.log(JSON.stringify(docs, null, 2));
     });
 
@@ -75,20 +90,65 @@ export function buildPrdyCli(): Command {
     .requiredOption('--project <path>', 'Project path')
     .option('--id <id>', 'PRD document id')
     .action(async (options: ShowCommandOptions) => {
-      if (options.id !== undefined) {
-        const docs = await listPrds(options.project);
-        const match = docs.find((doc) => doc.id === options.id);
+      const doc = await serviceFor(options.project).get(options.id);
+      console.log(JSON.stringify(doc, null, 2));
+    });
 
-        if (match === undefined) {
-          throw new Error(`PRD id not found: ${options.id}`);
-        }
+  prdy
+    .command('import')
+    .description('Import a YAML PRD document (validated; conflicts propose a successor)')
+    .requiredOption('--project <path>', 'Project path')
+    .requiredOption('--file <file>', 'Path to YAML PRD document')
+    .option('--accept-successor', 'Accept a conflicted import as the next version')
+    .action(async (options: ImportCommandOptions) => {
+      const service = serviceFor(options.project);
+      const input = { filePath: options.file };
 
-        console.log(JSON.stringify(match, null, 2));
+      if (options.acceptSuccessor) {
+        const successor = await service.acceptSuccessor(input);
+        console.log(
+          JSON.stringify(
+            {
+              ok: true,
+              outcome: 'successor-accepted',
+              id: successor.id,
+              version: successor.version,
+            },
+            null,
+            2,
+          ),
+        );
         return;
       }
 
-      const doc = await loadPrd(options.project);
-      console.log(JSON.stringify(doc, null, 2));
+      const result = await service.importDocument(input);
+      console.log(
+        JSON.stringify(
+          {
+            ok: true,
+            outcome: result.kind,
+            id: result.document.id,
+            version: result.document.version,
+            status: result.document.status,
+          },
+          null,
+          2,
+        ),
+      );
+    });
+
+  prdy
+    .command('export')
+    .description('Render a PRD to a labeled generated-view Markdown file')
+    .requiredOption('--project <path>', 'Project path')
+    .option('--id <id>', 'PRD document id')
+    .option('--out <path>', 'Output path (default docs/prdy/<id>.md)')
+    .action(async (options: ExportCommandOptions) => {
+      const result = await serviceFor(options.project).exportMarkdown({
+        id: options.id,
+        outPath: options.out,
+      });
+      console.log(JSON.stringify({ ok: true, filePath: result.filePath }, null, 2));
     });
 
   return program;

packages/prdy/src/index.ts

@@ -1,12 +1,35 @@
-export { createPrd, loadPrd, savePrd, listPrds } from './prd.js';
+// PrdService is the single authority surface for PRD documents. The raw store
+// writers (createPrd/savePrd) are deliberately NOT exported: every mutation
+// goes through the service so there is no second writer path.
+export { loadPrd, listPrds, parsePrdDocument } from './prd.js';
 export { runPrdWizard } from './wizard.js';
 export { buildPrdyCli, runPrdyCli } from './cli.js';
 export { BUILTIN_PRD_TEMPLATES, resolveTemplate } from './templates.js';
+export {
+  PrdService,
+  PRD_GENERATED_VIEW_LABEL,
+  PrdError,
+  PrdNotFoundError,
+  PrdUpdateError,
+  PrdImportInvalidError,
+  PrdImportConflictError,
+} from './service.js';
 export type {
   PrdStatus,
   PrdTemplate,
   PrdTemplateSection,
   PrdSection,
+  PrdMissionLinkage,
   PrdDocument,
   CreatePrdOptions,
+  PrdServiceOptions,
+  PrdCreateInput,
+  PrdSectionPatch,
+  PrdUpdateInput,
+  PrdLinkMissionInput,
+  PrdPlanForMissionInput,
+  PrdExportInput,
+  PrdExportResult,
+  PrdImportInput,
+  PrdImportResult,
 } from './types.js';

packages/prdy/src/prd.ts

@@ -17,17 +17,49 @@ const prdSectionSchema = z.object({
   fields: z.record(z.string(), z.string()),
 });
 
+const prdMissionLinkageSchema = z.object({
+  missionId: z.string().min(1),
+  missionVersion: z.string().min(1),
+  prdVersion: z.number().int().min(1),
+  requirementIds: z.array(z.string()),
+  linkedAt: z.string().datetime(),
+});
+
 const prdDocumentSchema = z.object({
   id: z.string().min(1),
   title: z.string().min(1),
   status: z.enum(['draft', 'review', 'approved', 'archived']),
   projectPath: z.string().min(1),
   template: z.string().min(1),
+  // Defaults keep documents written by older prdy versions loadable.
+  version: z.number().int().min(1).default(1),
   sections: z.array(prdSectionSchema),
+  missions: z.array(prdMissionLinkageSchema).default([]),
   createdAt: z.string().datetime(),
   updatedAt: z.string().datetime(),
 });
 
+/** YAML timestamp scalars are parsed as Date by some emitters — normalize to ISO strings. */
+function coerceTimestamps(value: unknown): unknown {
+  if (value instanceof Date) {
+    return value.toISOString();
+  }
+  if (Array.isArray(value)) {
+    return value.map(coerceTimestamps);
+  }
+  if (typeof value === 'object' && value !== null) {
+    return Object.fromEntries(
+      Object.entries(value).map(([key, entry]) => [key, coerceTimestamps(entry)]),
+    );
+  }
+  return value;
+}
+
+/** Validate an unknown value as a PRD document (throws zod errors on failure). */
+export function parsePrdDocument(value: unknown): PrdDocument {
+  return prdDocumentSchema.parse(coerceTimestamps(value)) as PrdDocument;
+}
+
 function expandHome(projectPath: string): string {
   if (!projectPath.startsWith('~')) {
     return projectPath;
@@ -74,6 +106,8 @@ function prdDirectory(projectPath: string): string {
   return path.join(projectPath, PRD_DIRECTORY);
 }
 
+export { prdDirectory };
+
 function prdFilePath(projectPath: string, id: string): string {
   return path.join(prdDirectory(projectPath), `${id}.yaml`);
 }
@@ -113,11 +147,13 @@ export async function createPrd(options: CreatePrdOptions): Promise<PrdDocument>
     status: 'draft',
     projectPath: resolvedProjectPath,
     template: template.id,
+    version: 1,
     sections: template.sections.map((section) => ({
       id: section.id,
       title: section.title,
       fields: Object.fromEntries(section.fields.map((field) => [field, ''])),
     })),
+    missions: [],
     createdAt: now,
     updatedAt: now,
   };
@@ -190,7 +226,7 @@ export async function listPrds(projectPath: string): Promise<PrdDocument[]> {
       throw new Error(`Failed to parse PRD file ${filePath}: ${String(error)}`);
     }
 
-    const document = prdDocumentSchema.parse(parsed);
+    const document = parsePrdDocument(parsed);
     documents.push(document);
   }
 

packages/prdy/src/service.spec.ts

@@ -0,0 +1,433 @@
+import { existsSync } from 'node:fs';
+import { mkdtemp, readFile, readdir, writeFile } from 'node:fs/promises';
+import os from 'node:os';
+import path from 'node:path';
+
+import yaml from 'js-yaml';
+import { beforeEach, describe, expect, it } from 'vitest';
+
+import {
+  PRD_GENERATED_VIEW_LABEL,
+  PrdImportConflictError,
+  PrdImportInvalidError,
+  PrdNotFoundError,
+  PrdService,
+  PrdUpdateError,
+} from './index.js';
+import type { PrdDocument } from './index.js';
+
+// ── Helpers ──────────────────────────────────────────────────────────────────
+
+let projectDir: string;
+
+async function makeProject(): Promise<string> {
+  return mkdtemp(path.join(os.tmpdir(), 'prdy-service-'));
+}
+
+function service(): PrdService {
+  return new PrdService({ projectPath: projectDir });
+}
+
+function storeDir(): string {
+  return path.join(projectDir, 'docs', 'prdy');
+}
+
+/** Handcraft a full, schema-valid PRD document for import scenarios. */
+function importFixture(overrides: Partial<PrdDocument> = {}): PrdDocument {
+  return {
+    id: 'imported-prd-20260101-000000',
+    title: 'Imported PRD',
+    status: 'draft',
+    projectPath: '/tmp/elsewhere',
+    template: 'software',
+    version: 1,
+    sections: [
+      { id: 'introduction', title: 'Introduction', fields: { context: '', objective: '' } },
+      {
+        id: 'scope-non-goals',
+        title: 'Scope / Non-Goals',
+        fields: { inScope: '', outOfScope: '' },
+      },
+    ],
+    missions: [],
+    createdAt: '2026-01-01T00:00:00.000Z',
+    updatedAt: '2026-01-01T00:00:00.000Z',
+    ...overrides,
+  };
+}
+
+async function writeImportFile(doc: PrdDocument): Promise<string> {
+  const filePath = path.join(projectDir, `${doc.id}.import.yaml`);
+  await writeFile(filePath, yaml.dump(doc), 'utf8');
+  return filePath;
+}
+
+beforeEach(async () => {
+  projectDir = await makeProject();
+});
+
+// ── Single authority store (AC: prdy path and mission path resolve to the
+//    SAME store under docs/prdy/ with stable ids/versions) ────────────────────
+
+describe('PrdService single authority store', () => {
+  it('persists PRDs from the prdy path and the mission path into the same docs/prdy store', async () => {
+    const direct = await service().create({ name: 'Direct PRD' });
+    const viaMission = await service().planForMission({
+      name: 'Mission PRD',
+      missionId: 'mission-1',
+      missionVersion: '2026-01-01T00:00:00.000Z',
+    });
+
+    const files = await readdir(storeDir());
+    expect(files).toContain(`${direct.id}.yaml`);
+    expect(files).toContain(`${viaMission.id}.yaml`);
+
+    // A fresh service instance (new process equivalent) resolves both.
+    const all = await service().list();
+    expect(all.map((doc) => doc.id).sort()).toEqual([direct.id, viaMission.id].sort());
+
+    // Stable versions: creation is v1; linkage writes do not bump content version.
+    expect((await service().get(direct.id)).version).toBe(1);
+    expect((await service().get(viaMission.id)).version).toBe(1);
+  });
+
+  it('round-trips documents through the store with identity intact', async () => {
+    const created = await service().create({ name: 'Round Trip', template: 'feature' });
+    const fresh = await service().get(created.id);
+
+    expect(fresh).toEqual(created);
+    expect(fresh.id).toBe(created.id);
+    expect(fresh.template).toBe('feature');
+    expect(fresh.status).toBe('draft');
+  });
+
+  it('throws a typed error for unknown ids and empty stores', async () => {
+    await expect(service().get('nope')).rejects.toBeInstanceOf(PrdNotFoundError);
+    await expect(service().get()).rejects.toBeInstanceOf(PrdNotFoundError);
+  });
+});
+
+// ── Mission linkage persistence (AC: linkage survives restart via fresh
+//    service instances) ────────────────────────────────────────────────────────
+
+describe('PrdService mission linkage', () => {
+  it('persists linkage and reads it back from a fresh service instance', async () => {
+    const created = await service().planForMission({
+      name: 'Linked PRD',
+      missionId: 'mission-42',
+      missionVersion: '2026-02-03T04:05:06.000Z',
+      requirementIds: ['FR-1', 'FR-2'],
+    });
+
+    // Fresh instance — nothing in memory from the creating call.
+    const links = await service().listMissionLinks(created.id);
+    expect(links).toHaveLength(1);
+    expect(links[0]).toMatchObject({
+      missionId: 'mission-42',
+      missionVersion: '2026-02-03T04:05:06.000Z',
+      prdVersion: 1,
+      requirementIds: ['FR-1', 'FR-2'],
+    });
+
+    // Linkage is carried in the YAML authority file itself.
+    const raw = await readFile(path.join(storeDir(), `${created.id}.yaml`), 'utf8');
+    const persisted = yaml.load(raw) as PrdDocument;
+    expect(persisted.missions[0]?.missionId).toBe('mission-42');
+    expect(persisted.missions[0]?.requirementIds).toEqual(['FR-1', 'FR-2']);
+  });
+
+  it('refreshes an existing linkage entry in place instead of duplicating', async () => {
+    const created = await service().planForMission({
+      name: 'Relink PRD',
+      missionId: 'mission-7',
+      missionVersion: 'v1',
+    });
+
+    await service().update({
+      id: created.id,
+      sections: [{ id: 'introduction', fields: { objective: 'Ship it' } }],
+    });
+
+    const relinked = await service().linkMission({
+      prdId: created.id,
+      missionId: 'mission-7',
+      missionVersion: 'v2',
+      requirementIds: ['NFR-1'],
+    });
+
+    expect(relinked.missions).toHaveLength(1);
+    expect(relinked.missions[0]).toMatchObject({ missionVersion: 'v2', prdVersion: 2 });
+  });
+
+  it('does not bump the content version when writing linkage', async () => {
+    const created = await service().create({ name: 'Stable Version' });
+    const linked = await service().linkMission({
+      prdId: created.id,
+      missionId: 'm',
+      missionVersion: 'v1',
+    });
+    expect(linked.version).toBe(1);
+  });
+});
+
+// ── Update semantics ──────────────────────────────────────────────────────────
+
+describe('PrdService update', () => {
+  it('applies section patches and bumps the content version', async () => {
+    const created = await service().create({ name: 'Updatable' });
+    const updated = await service().update({
+      id: created.id,
+      sections: [{ id: 'introduction', fields: { context: 'Some context', objective: 'Goal' } }],
+    });
+
+    expect(updated.version).toBe(2);
+    expect(updated.sections[0]?.fields).toMatchObject({
+      context: 'Some context',
+      objective: 'Goal',
+    });
+    expect((await service().get(created.id)).version).toBe(2);
+  });
+
+  it('refuses unknown section ids with a typed error', async () => {
+    const created = await service().create({ name: 'Strict' });
+    await expect(
+      service().update({ id: created.id, sections: [{ id: 'nope', fields: {} }] }),
+    ).rejects.toBeInstanceOf(PrdUpdateError);
+  });
+});
+
+// ── Markdown export is a labeled generated view, never authority ──────────────
+
+describe('PrdService exportMarkdown', () => {
+  it('writes a generated view carrying the label and source identity', async () => {
+    const created = await service().create({ name: 'Exported PRD' });
+    const result = await service().exportMarkdown({ id: created.id });
+
+    expect(result.filePath).toBe(path.join(storeDir(), `${created.id}.md`));
+    expect(result.content).toContain(PRD_GENERATED_VIEW_LABEL);
+    expect(result.content).toContain(`prd-id: ${created.id}`);
+    expect(result.content).toContain('prd-version: 1');
+    expect(result.content).toContain(`source-of-truth: docs/prdy/${created.id}.yaml`);
+  });
+
+  it('reflects the current version after updates', async () => {
+    const created = await service().create({ name: 'Versioned Export' });
+    await service().update({
+      id: created.id,
+      sections: [{ id: 'introduction', fields: { objective: 'v2 goal' } }],
+    });
+    const result = await service().exportMarkdown({ id: created.id });
+    expect(result.content).toContain('prd-version: 2');
+  });
+
+  it('NEGATIVE CONTROL: mutating the exported Markdown cannot change the authority', async () => {
+    const created = await service().create({ name: 'Guarded PRD' });
+    const before = structuredClone(await service().get(created.id));
+
+    const result = await service().exportMarkdown({ id: created.id });
+    await writeFile(
+      result.filePath,
+      `<!-- ${PRD_GENERATED_VIEW_LABEL} -->\n# FAKE\nprd-id: fake-id\nprd-version: 99\n`,
+      'utf8',
+    );
+
+    const after = await service().get(created.id);
+    expect(after).toEqual(before);
+    expect(after.version).toBe(1);
+    expect(after.title).toBe(before.title);
+  });
+
+  it('never parses Markdown files that sit in the store directory', async () => {
+    const created = await service().create({ name: 'Decoy Guard' });
+
+    // A decoy .md file with invalid YAML must be invisible to the store.
+    await writeFile(path.join(storeDir(), 'decoy.md'), 'not: [valid: yaml', 'utf8');
+    // And a decoy .yaml-named Markdown body must not silently validate either.
+    await service().exportMarkdown({ id: created.id });
+
+    const listed = await service().list();
+    expect(listed.map((doc) => doc.id)).toEqual([created.id]);
+    await expect(service().get(created.id)).resolves.toBeTruthy();
+  });
+});
+
+// ── Import: validated, conflict-aware, never silently merging ─────────────────
+
+describe('PrdService importDocument', () => {
+  it('creates a valid import through the service, as draft — validity is not approval', async () => {
+    const filePath = await writeImportFile(importFixture({ status: 'approved' }));
+
+    const result = await service().importDocument({ filePath });
+
+    expect(result.kind).toBe('created');
+    expect(result.document.id).toBe('imported-prd-20260101-000000');
+    expect(result.document.status).toBe('draft'); // structural validity ≠ approval
+    expect(result.document.version).toBe(1);
+
+    const persisted = await service().get('imported-prd-20260101-000000');
+    expect(persisted.status).toBe('draft');
+
+    const files = await readdir(storeDir());
+    expect(files).toContain('imported-prd-20260101-000000.yaml');
+  });
+
+  it('reports identical content as a no-op without writing', async () => {
+    const created = await service().create({ name: 'Existing PRD' });
+    const before = await readFile(path.join(storeDir(), `${created.id}.yaml`), 'utf8');
+
+    const filePath = await writeImportFile(importFixture({ ...created }));
+    const result = await service().importDocument({ filePath });
+
+    expect(result.kind).toBe('identical');
+    const after = await readFile(path.join(storeDir(), `${created.id}.yaml`), 'utf8');
+    expect(after).toBe(before);
+  });
+
+  it('refuses a conflicting import with a typed error, a proposed successor, and untouched bytes', async () => {
+    const existing = await service().create({ name: 'Authority PRD' });
+    await service().linkMission({
+      prdId: existing.id,
+      missionId: 'mission-keep',
+      missionVersion: 'v1',
+      requirementIds: ['FR-0'],
+    });
+    const beforeBytes = await readFile(path.join(storeDir(), `${existing.id}.yaml`), 'utf8');
+
+    const divergent = importFixture({
+      ...existing,
+      title: 'Divergent Title',
+      sections: [
+        {
+          id: 'introduction',
+          title: 'Introduction',
+          fields: { context: 'changed', objective: '' },
+        },
+      ],
+    });
+    const filePath = await writeImportFile(divergent);
+
+    const attempt = service().importDocument({ filePath });
+    let caught: unknown;
+    try {
+      await attempt;
+    } catch (error) {
+      caught = error;
+    }
+    expect(caught).toBeInstanceOf(PrdImportConflictError);
+
+    const error = caught as PrdImportConflictError;
+    expect(error.code).toBe('PRD_IMPORT_CONFLICT');
+    expect(error.existing.id).toBe(existing.id);
+    expect(error.proposal.version).toBe(existing.version + 1); // successor proposal
+    expect(error.proposal.status).toBe('draft');
+
+    // Original authority content untouched on disk.
+    const afterBytes = await readFile(path.join(storeDir(), `${existing.id}.yaml`), 'utf8');
+    expect(afterBytes).toBe(beforeBytes);
+  });
+
+  it('acceptSuccessor persists the proposal explicitly, carrying linkages forward', async () => {
+    const existing = await service().create({ name: 'Successor Base' });
+    await service().linkMission({
+      prdId: existing.id,
+      missionId: 'mission-keep',
+      missionVersion: 'v1',
+    });
+
+    const divergent = importFixture({
+      ...existing,
+      title: 'Accepted Successor Title',
+    });
+    const filePath = await writeImportFile(divergent);
+
+    const successor = await service().acceptSuccessor({ filePath });
+    expect(successor.id).toBe(existing.id);
+    expect(successor.version).toBe(existing.version + 1);
+    expect(successor.title).toBe('Accepted Successor Title');
+    expect(successor.status).toBe('draft');
+    expect(successor.missions.map((m) => m.missionId)).toEqual(['mission-keep']);
+
+    // Persisted for a fresh reader.
+    const fresh = await service().get(existing.id);
+    expect(fresh.version).toBe(2);
+    expect(fresh.title).toBe('Accepted Successor Title');
+  });
+
+  it('refuses structurally-invalid imports with a typed error and creates nothing', async () => {
+    const cases: Array<{ name: string; body: string }> = [
+      { name: 'missing-title.yaml', body: yaml.dump({ id: 'x', status: 'draft' }) },
+      {
+        name: 'bad-status.yaml',
+        body: yaml.dump(importFixture({ status: 'not-a-status' as PrdDocument['status'] })),
+      },
+      {
+        name: 'bad-version.yaml',
+        body: yaml.dump(importFixture({ version: 0 })),
+      },
+      { name: 'not-yaml.yaml', body: '::: not yaml [\n  - {' },
+    ];
+
+    for (const fixture of cases) {
+      const filePath = path.join(projectDir, fixture.name);
+      await writeFile(filePath, fixture.body, 'utf8');
+
+      await expect(service().importDocument({ filePath })).rejects.toBeInstanceOf(
+        PrdImportInvalidError,
+      );
+    }
+
+    // Nothing was created: the authority store does not even exist yet.
+    await expect(readdir(storeDir())).rejects.toMatchObject({ code: 'ENOENT' });
+  });
+
+  it('acceptSuccessor refuses when there is no existing document to succeed', async () => {
+    const filePath = await writeImportFile(importFixture());
+    await expect(service().acceptSuccessor({ filePath })).rejects.toBeInstanceOf(PrdNotFoundError);
+  });
+});
+
+// ── No second writer: no code path reads exported Markdown back into authority ─
+
+describe('no-second-writer invariant (source-level)', () => {
+  // Resolve the package source dir whether vitest runs from the package root
+  // (turbo/pnpm test) or from the worktree root.
+  function resolveSrcDir(): string {
+    const candidates = [path.resolve('src'), path.resolve('packages/prdy/src')];
+    return candidates.find((dir) => existsSync(path.join(dir, 'service.ts'))) ?? candidates[0]!;
+  }
+
+  const srcDir = resolveSrcDir();
+  const sourceFiles = [
+    'cli.ts',
+    'index.ts',
+    'prd.ts',
+    'service.ts',
+    'templates.ts',
+    'types.ts',
+    'wizard.ts',
+  ];
+
+  it('no source file in @mosaicstack/prdy reads a .md file', async () => {
+    for (const file of sourceFiles) {
+      const text = await readFile(path.join(srcDir, file), 'utf8');
+      const readLines = text
+        .split('\n')
+        .map((line) => line.trim())
+        .filter((line) => /readFile|readFileSync|createReadStream/.test(line));
+
+      for (const line of readLines) {
+        expect(line.includes('.md'), `${file} reads a Markdown file: ${line}`).toBe(false);
+      }
+    }
+  });
+
+  it('the mosaic prdy/mission adapters never read a .md file', async () => {
+    const adapterDir = path.resolve(srcDir, '..', '..', 'mosaic', 'src', 'commands');
+    for (const file of ['prdy.ts', 'mission.ts']) {
+      const text = await readFile(path.join(adapterDir, file), 'utf8');
+      expect(text.includes("'.md'") || text.includes('.md`'), `${file} references a .md path`).toBe(
+        false,
+      );
+    }
+  });
+});

packages/prdy/src/service.ts

@@ -0,0 +1,379 @@
+import { promises as fs } from 'node:fs';
+import path from 'node:path';
+
+import yaml from 'js-yaml';
+
+import { createPrd, listPrds, parsePrdDocument, prdDirectory, savePrd } from './prd.js';
+import type {
+  PrdCreateInput,
+  PrdDocument,
+  PrdExportInput,
+  PrdExportResult,
+  PrdImportInput,
+  PrdImportResult,
+  PrdLinkMissionInput,
+  PrdMissionLinkage,
+  PrdPlanForMissionInput,
+  PrdServiceOptions,
+  PrdUpdateInput,
+} from './types.js';
+
+/**
+ * PrdService is the SINGLE authority surface for PRD documents.
+ *
+ * Every mutation path (CLI wizard, `mosaic mission --plan`, import) routes
+ * through this service; the YAML store under `docs/prdy/` is the authority and
+ * exported Markdown is a generated view that no code path reads back.
+ */
+
+// ── Typed errors ───────────────────────────────────────────────────────────────
+
+export class PrdError extends Error {
+  constructor(
+    message: string,
+    readonly code: string,
+  ) {
+    super(message);
+    this.name = 'PrdError';
+  }
+}
+
+export class PrdNotFoundError extends PrdError {
+  constructor(message: string) {
+    super(message, 'PRD_NOT_FOUND');
+    this.name = 'PrdNotFoundError';
+  }
+}
+
+export class PrdUpdateError extends PrdError {
+  constructor(message: string) {
+    super(message, 'PRD_UPDATE_INVALID');
+    this.name = 'PrdUpdateError';
+  }
+}
+
+/** Structural refusal: the import payload failed schema validation. Nothing is written. */
+export class PrdImportInvalidError extends PrdError {
+  constructor(
+    message: string,
+    readonly issues?: string,
+  ) {
+    super(message, 'PRD_IMPORT_INVALID');
+    this.name = 'PrdImportInvalidError';
+  }
+}
+
+/**
+ * Conflict refusal: an existing PRD shares the imported id but the content
+ * diverges. Carries a PROPOSED successor (existing version + 1) that is only
+ * persisted via an explicit {@link PrdService.acceptSuccessor} call — import
+ * never overwrites and never merges.
+ */
+export class PrdImportConflictError extends PrdError {
+  constructor(
+    message: string,
+    readonly existing: PrdDocument,
+    readonly proposal: PrdDocument,
+  ) {
+    super(message, 'PRD_IMPORT_CONFLICT');
+    this.name = 'PrdImportConflictError';
+  }
+}
+
+// ── Service ────────────────────────────────────────────────────────────────────
+
+/** The generated-view label carried by every Markdown export. */
+export const PRD_GENERATED_VIEW_LABEL = 'generated view — do not edit';
+
+export class PrdService {
+  private readonly projectPath: string;
+
+  constructor(options: PrdServiceOptions) {
+    this.projectPath = options.projectPath;
+  }
+
+  /** Create a new PRD (version 1, draft) in the authority store. */
+  async create(input: PrdCreateInput): Promise<PrdDocument> {
+    return createPrd({
+      name: input.name,
+      projectPath: this.projectPath,
+      template: input.template,
+      interactive: false,
+    });
+  }
+
+  /** Read a PRD by id, or the most recently updated one. */
+  async get(id?: string): Promise<PrdDocument> {
+    const documents = await listPrds(this.projectPath);
+
+    if (id === undefined) {
+      const latest = documents[0];
+      if (latest === undefined) {
+        throw new PrdNotFoundError(`No PRD documents found under docs/prdy/ for this project`);
+      }
+      return latest;
+    }
+
+    const match = documents.find((doc) => doc.id === id);
+    if (match === undefined) {
+      throw new PrdNotFoundError(`PRD id not found: ${id}`);
+    }
+    return match;
+  }
+
+  /** List all PRDs in the authority store (most recently updated first). */
+  async list(): Promise<PrdDocument[]> {
+    return listPrds(this.projectPath);
+  }
+
+  /**
+   * Apply section field patches and bump the content version.
+   * Linkage entries are preserved; linkage writes do NOT bump the version.
+   */
+  async update(input: PrdUpdateInput): Promise<PrdDocument> {
+    const doc = await this.get(input.id);
+
+    for (const patch of input.sections) {
+      const section = doc.sections.find((candidate) => candidate.id === patch.id);
+      if (section === undefined) {
+        throw new PrdUpdateError(`Unknown section id: ${patch.id}`);
+      }
+      for (const [field, value] of Object.entries(patch.fields)) {
+        if (!(field in section.fields)) {
+          throw new PrdUpdateError(`Unknown field "${field}" on section "${patch.id}"`);
+        }
+        section.fields[field] = value;
+      }
+    }
+
+    doc.version += 1;
+    doc.updatedAt = new Date().toISOString();
+    await savePrd(doc);
+    return doc;
+  }
+
+  /**
+   * Record (or refresh) a mission ↔ PRD linkage on the PRD document.
+   * Persisted in the YAML authority, so it survives restarts.
+   */
+  async linkMission(input: PrdLinkMissionInput): Promise<PrdDocument> {
+    const doc = await this.get(input.prdId);
+    return this.applyLinkage(doc, input);
+  }
+
+  /** Read back the mission linkages recorded on a PRD. */
+  async listMissionLinks(prdId?: string): Promise<PrdMissionLinkage[]> {
+    const doc = await this.get(prdId);
+    return doc.missions;
+  }
+
+  /**
+   * Mission planning path: create a PRD for a mission AND persist the
+   * mission↔PRD linkage in a single authority write.
+   */
+  async planForMission(input: PrdPlanForMissionInput): Promise<PrdDocument> {
+    const doc = await this.create({ name: input.name, template: input.template });
+    return this.applyLinkage(doc, {
+      prdId: doc.id,
+      missionId: input.missionId,
+      missionVersion: input.missionVersion,
+      requirementIds: input.requirementIds,
+    });
+  }
+
+  /**
+   * Render the PRD to a Markdown GENERATED VIEW.
+   *
+   * The output carries source identity (PRD id + version + generated-view
+   * label). It is written under `docs/prdy/<id>.md` and is NEVER read back:
+   * the authority store only loads `.yaml`/`.yml` files, and no code path in
+   * this package parses the exported Markdown.
+   */
+  async exportMarkdown(input?: PrdExportInput): Promise<PrdExportResult> {
+    const doc = await this.get(input?.id);
+    const content = renderMarkdown(doc);
+    const filePath = input?.outPath ?? path.join(prdDirectory(doc.projectPath), `${doc.id}.md`);
+
+    await fs.mkdir(path.dirname(filePath), { recursive: true });
+    await fs.writeFile(filePath, content, 'utf8');
+    return { filePath, content };
+  }
+
+  /**
+   * Import a YAML PRD document.
+   *
+   * Structural validation (zod) happens BEFORE anything is proposed or
+   * written. A structurally-valid import is persisted as `draft` — validity is
+   * NOT approval. If an existing PRD shares the id with divergent content, a
+   * typed {@link PrdImportConflictError} is thrown carrying a proposed
+   * successor; the original authority document is left byte-identical on disk.
+   */
+  async importDocument(input: PrdImportInput): Promise<PrdImportResult> {
+    const incoming = await this.readImportFile(input.filePath);
+
+    const existing = (await listPrds(this.projectPath)).find((doc) => doc.id === incoming.id);
+    if (existing === undefined) {
+      const document = this.buildImportedDocument(incoming);
+      await savePrd(document);
+      return { kind: 'created', document };
+    }
+
+    if (canonicalCore(existing) === canonicalCore(incoming)) {
+      return { kind: 'identical', document: existing };
+    }
+
+    throw new PrdImportConflictError(
+      `PRD id "${incoming.id}" already exists with divergent content — refusing to overwrite. ` +
+        `Proposed successor: version ${existing.version + 1} (draft). ` +
+        `Accept explicitly with acceptSuccessor().`,
+      existing,
+      this.buildSuccessor(existing, incoming),
+    );
+  }
+
+  /**
+   * Explicitly accept a conflicted import as a successor version of the
+   * existing PRD. Re-validates the source file before writing; the successor
+   * is persisted with status `draft` (acceptance of the import is not approval
+   * of the PRD) and the existing mission linkages are carried forward.
+   */
+  async acceptSuccessor(input: PrdImportInput): Promise<PrdDocument> {
+    const incoming = await this.readImportFile(input.filePath);
+
+    const existing = (await listPrds(this.projectPath)).find((doc) => doc.id === incoming.id);
+    if (existing === undefined) {
+      throw new PrdNotFoundError(
+        `No existing PRD with id "${incoming.id}" — use importDocument to create it`,
+      );
+    }
+
+    const successor = this.buildSuccessor(existing, incoming);
+    await savePrd(successor);
+    return successor;
+  }
+
+  // ── internals ──────────────────────────────────────────────────────────────
+
+  private async applyLinkage(doc: PrdDocument, input: PrdLinkMissionInput): Promise<PrdDocument> {
+    const entry: PrdMissionLinkage = {
+      missionId: input.missionId,
+      missionVersion: input.missionVersion,
+      prdVersion: doc.version,
+      requirementIds: input.requirementIds ?? [],
+      linkedAt: new Date().toISOString(),
+    };
+
+    // One entry per mission: refresh in place if the mission is already linked.
+    const index = doc.missions.findIndex((m) => m.missionId === entry.missionId);
+    if (index === -1) {
+      doc.missions.push(entry);
+    } else {
+      doc.missions[index] = entry;
+    }
+
+    // Linkage is mission-side metadata, not a content revision: bump the
+    // timestamp only so ids/versions stay stable for consumers.
+    doc.updatedAt = new Date().toISOString();
+    await savePrd(doc);
+    return doc;
+  }
+
+  private async readImportFile(filePath: string): Promise<PrdDocument> {
+    let raw: string;
+    try {
+      raw = await fs.readFile(filePath, 'utf8');
+    } catch (error) {
+      throw new PrdImportInvalidError(`Cannot read import file ${filePath}: ${String(error)}`);
+    }
+
+    let parsed: unknown;
+    try {
+      parsed = yaml.load(raw);
+    } catch (error) {
+      throw new PrdImportInvalidError(`Import file is not valid YAML: ${String(error)}`);
+    }
+
+    try {
+      return parsePrdDocument(parsed);
+    } catch (error) {
+      throw new PrdImportInvalidError(
+        `Import file failed PRD schema validation: ${filePath}`,
+        error instanceof Error ? error.message : String(error),
+      );
+    }
+  }
+
+  private buildImportedDocument(incoming: PrdDocument): PrdDocument {
+    const now = new Date().toISOString();
+    return {
+      ...incoming,
+      // The import lands in THIS project's authority store.
+      projectPath: this.projectPath,
+      // A structurally-valid import is not thereby approved.
+      status: 'draft',
+      version: 1,
+      missions: [],
+      createdAt: now,
+      updatedAt: now,
+    };
+  }
+
+  private buildSuccessor(existing: PrdDocument, incoming: PrdDocument): PrdDocument {
+    return {
+      ...incoming,
+      id: existing.id,
+      projectPath: existing.projectPath,
+      status: 'draft',
+      version: existing.version + 1,
+      missions: existing.missions,
+      createdAt: existing.createdAt,
+      updatedAt: new Date().toISOString(),
+    };
+  }
+}
+
+// ── Markdown rendering (generated view) ───────────────────────────────────────
+
+function canonicalCore(doc: PrdDocument): string {
+  return JSON.stringify([doc.title, doc.template, doc.sections]);
+}
+
+function renderMarkdown(doc: PrdDocument): string {
+  const lines: string[] = [
+    '<!--',
+    `${PRD_GENERATED_VIEW_LABEL}`,
+    `source-of-truth: docs/prdy/${doc.id}.yaml (YAML authority)`,
+    `prd-id: ${doc.id}`,
+    `prd-version: ${doc.version}`,
+    `generated-at: ${new Date().toISOString()}`,
+    '-->',
+    '',
+    `# ${doc.title}`,
+    '',
+    `**Status:** ${doc.status} · **Version:** ${doc.version} · **Template:** ${doc.template}`,
+    '',
+  ];
+
+  if (doc.missions.length > 0) {
+    lines.push('## Mission Linkage', '');
+    for (const mission of doc.missions) {
+      const requirements =
+        mission.requirementIds.length > 0 ? mission.requirementIds.join(', ') : 'none selected';
+      lines.push(
+        `- mission \`${mission.missionId}\` @ version \`${mission.missionVersion}\`` +
+          ` (linked at PRD v${mission.prdVersion}) — requirements: ${requirements}`,
+      );
+    }
+    lines.push('');
+  }
+
+  for (const section of doc.sections) {
+    lines.push(`## ${section.title}`, '');
+    for (const [field, value] of Object.entries(section.fields)) {
+      lines.push(`### ${field}`, '', value.trim().length > 0 ? value : '_Not set_.', '');
+    }
+  }
+
+  lines.push('---', '', `_End of generated view for ${doc.id} v${doc.version}._`, '');
+  return lines.join('\n');
+}

packages/prdy/src/types.ts

@@ -19,13 +19,31 @@ export interface PrdSection {
   fields: Record<string, string>;
 }
 
+/**
+ * Mission ↔ PRD linkage recorded on the PRD document (the YAML authority).
+ *
+ * `missionVersion` is the mission-side revision marker available to the CLI
+ * (the gateway exposes `updatedAt` for missions — there is no numeric mission
+ * version yet). `prdVersion` snapshots the PRD content version at link time.
+ */
+export interface PrdMissionLinkage {
+  missionId: string;
+  missionVersion: string;
+  prdVersion: number;
+  requirementIds: string[];
+  linkedAt: string;
+}
+
 export interface PrdDocument {
   id: string;
   title: string;
   status: PrdStatus;
   projectPath: string;
   template: string;
+  /** Content revision counter. Bumped by updates and accepted imports. */
+  version: number;
   sections: PrdSection[];
+  missions: PrdMissionLinkage[];
   createdAt: string;
   updatedAt: string;
 }
@@ -36,3 +54,60 @@ export interface CreatePrdOptions {
   template?: string;
   interactive?: boolean;
 }
+
+// ── PrdService surface (single authority entry point) ─────────────────────────
+
+export interface PrdServiceOptions {
+  projectPath: string;
+}
+
+export interface PrdCreateInput {
+  name: string;
+  template?: string;
+}
+
+export interface PrdSectionPatch {
+  id: string;
+  fields: Record<string, string>;
+}
+
+export interface PrdUpdateInput {
+  /** Defaults to the most recently updated PRD. */
+  id?: string;
+  sections: PrdSectionPatch[];
+}
+
+export interface PrdLinkMissionInput {
+  /** Defaults to the most recently updated PRD. */
+  prdId?: string;
+  missionId: string;
+  missionVersion: string;
+  requirementIds?: string[];
+}
+
+export interface PrdPlanForMissionInput extends PrdLinkMissionInput {
+  name: string;
+  template?: string;
+}
+
+export interface PrdExportInput {
+  /** Defaults to the most recently updated PRD. */
+  id?: string;
+  /** Override the generated-view output path. */
+  outPath?: string;
+}
+
+export interface PrdExportResult {
+  filePath: string;
+  content: string;
+}
+
+/** Discriminated result of a non-conflicting import. */
+export type PrdImportResult =
+  | { kind: 'created'; document: PrdDocument }
+  | { kind: 'identical'; document: PrdDocument };
+
+export interface PrdImportInput {
+  /** Path to a YAML-serialized PRD document (NOT the generated Markdown view). */
+  filePath: string;
+}

packages/prdy/src/wizard.ts

@@ -2,8 +2,8 @@ import path from 'node:path';
 
 import { cancel, intro, isCancel, outro, select, text } from '@clack/prompts';
 
-import { createPrd, savePrd } from './prd.js';
-import type { CreatePrdOptions, PrdDocument } from './types.js';
+import { PrdService } from './service.js';
+import type { CreatePrdOptions, PrdDocument, PrdSectionPatch } from './types.js';
 
 interface WizardAnswers {
   goals: string;
@@ -11,20 +11,41 @@ interface WizardAnswers {
   milestones: string;
 }
 
-function updateSectionField(doc: PrdDocument, sectionKeyword: string, value: string): void {
-  const section = doc.sections.find((candidate) => candidate.id.includes(sectionKeyword));
+/**
+ * Translate wizard answers into section patches using the same keyword
+ * matching the wizard always used (first section whose id contains the
+ * keyword, then first field whose name contains it, else first field).
+ */
+function buildWizardPatches(doc: PrdDocument, answers: WizardAnswers): PrdSectionPatch[] {
+  const bySection = new Map<string, PrdSectionPatch>();
 
-  if (section === undefined) {
-    return;
-  }
+  const add = (keyword: string, value: string): void => {
+    const section = doc.sections.find((candidate) => candidate.id.includes(keyword));
+    if (section === undefined) {
+      return;
+    }
 
-  const fieldName =
-    Object.keys(section.fields).find((field) => field.toLowerCase().includes(sectionKeyword)) ??
-    Object.keys(section.fields)[0];
+    const fieldName =
+      Object.keys(section.fields).find((field) => field.toLowerCase().includes(keyword)) ??
+      Object.keys(section.fields)[0];
 
-  if (fieldName !== undefined) {
-    section.fields[fieldName] = value;
-  }
+    if (fieldName === undefined || section.fields[fieldName] === value) {
+      return;
+    }
+
+    const existing = bySection.get(section.id);
+    if (existing === undefined) {
+      bySection.set(section.id, { id: section.id, fields: { [fieldName]: value } });
+    } else {
+      existing.fields[fieldName] = value;
+    }
+  };
+
+  add('goal', answers.goals);
+  add('constraint', answers.constraints);
+  add('milestone', answers.milestones);
+
+  return [...bySection.values()];
 }
 
 async function promptText(message: string, initialValue = ''): Promise<string> {
@@ -63,15 +84,10 @@ async function promptTemplate(template?: string): Promise<string> {
   return choice;
 }
 
-function applyWizardAnswers(doc: PrdDocument, answers: WizardAnswers): PrdDocument {
-  updateSectionField(doc, 'goal', answers.goals);
-  updateSectionField(doc, 'constraint', answers.constraints);
-  updateSectionField(doc, 'milestone', answers.milestones);
-
-  doc.updatedAt = new Date().toISOString();
-  return doc;
-}
-
+/**
+ * Interactive PRD wizard. All writes go through PrdService — the wizard is a
+ * prompt layer, never a second writer path.
+ */
 export async function runPrdWizard(options: CreatePrdOptions): Promise<PrdDocument> {
   intro('Mosaic PRD wizard');
 
@@ -82,20 +98,15 @@ export async function runPrdWizard(options: CreatePrdOptions): Promise<PrdDocume
   const constraints = await promptText('Key constraints');
   const milestones = await promptText('Planned milestones');
 
-  const doc = await createPrd({
-    ...options,
+  const service = new PrdService({ projectPath: options.projectPath });
+  const doc = await service.create({
     name,
     template,
-    interactive: true,
   });
 
-  const updated = applyWizardAnswers(doc, {
-    goals,
-    constraints,
-    milestones,
-  });
-
-  await savePrd(updated);
+  const patches = buildWizardPatches(doc, { goals, constraints, milestones });
+  const updated =
+    patches.length > 0 ? await service.update({ id: doc.id, sections: patches }) : doc;
 
   outro(`PRD created: ${path.join(updated.projectPath, 'docs', 'prdy', `${updated.id}.yaml`)}`);
 

scratchpads/ri-4-001-prd-authority.md

@@ -0,0 +1,37 @@
+# Scratchpad — RI-4-001 One transitional PRD authority (RI-N3, #1275)
+
+- Objective: single PrdService authority in `@mosaicstack/prdy`; `mosaic prdy` and
+  `mission --plan` become thin adapters; mission↔PRD linkage persisted on disk;
+  Markdown export is a labeled generated view (never read back); import is
+  validated/conflict-aware with typed refusals.
+- Budget: ~35K tokens (card cap). Baselines: prdy build/lint rc=0, 0 tests;
+  mosaic build rc=0 (after root turbo build), lint rc=0, 1548 tests pass;
+  root build rc=0.
+- Plan: (1) extend store schema (version, missions linkage) (2) PrdService +
+  typed errors (3) wizard/cli route through service (4) mosaic adapters
+  (5) contract specs both packages (6) gates (7) sabotage control (8) report
+  to /var/tmp/ri-050/ri-4-001-report.md.
+- Decisions:
+  - Linkage lives ON the PRD document (`missions` array) — one authority file,
+    survives restart, no sidecar sync problems.
+  - `version` = content revision of sections/status (bumped by update/import
+    accept). Linkage writes bump `updatedAt` only, so ids/versions stay stable
+    for the card's "stable ids/versions" contract.
+  - Mission version marker = `mission.updatedAt` (gateway MissionInfo has no
+    numeric version field).
+  - Import reads YAML documents only — never the exported Markdown (keeps the
+    "no code path reads exported Markdown" invariant).
+  - Import of an existing id with identical core content → `identical` no-op;
+    divergent → typed `PrdImportConflictError` carrying proposed successor
+    (existing.version + 1, status draft, linkages preserved). Original bytes
+    untouched until explicit `acceptSuccessor`.
+  - `requirementIds` default `[]` at the mission command (no requirement
+    selection UI yet) — service accepts ids when a caller has them.
+- Progress log:
+  - [16:35] baselines captured (prdy 0 tests; mosaic 1548 after root build; root build rc=0)
+  - [16:38] store schema v2 + PrdService + wizard/cli rerouted; prdy build/lint green
+  - [16:40] mosaic adapters done; prdy spec 20/20 (found+fixed: import project-path leak, empty-store typed error, YAML timestamp coercion)
+  - [16:44] mosaic specs 9/9 (fixed commander from:'user' argv, vi.mock hoisting, restoreAllMocks wiping factory mocks)
+  - [16:45] all gates green; 4 commits (e291bfb, 2c5d208, a23826c, 540d6f1)
+  - [16:46] sabotage: linkage write removed → prdy 3 fail / mosaic 2 fail, 1548/1548 pre-existing pass; restored byte-identically; re-green 20/20 + 1557/1557
+  - [16:47] report written to /var/tmp/ri-050/ri-4-001-report.md — card complete