fix(T13891): one project snapshot per run for the unified cleo.db

.changeset/t13891-one-project-snapshot.md

@@ -0,0 +1,6 @@
+---
+id: t13891-one-project-snapshot
+tasks: [T13891]
+kind: fix
+summary: "session-end and pre-op snapshots write one tasks-*.db per run for the unified project cleo.db; brain and conduit are covered by it instead of getting hard links that diverged under per-prefix retention (or full copies where links are unsupported); listBrainBackups and backup verify read the project snapshot, and older brain-*/conduit-* files stay listed"
+---

packages/cleo/src/cli/commands/__tests__/backup-verify.test.ts

@@ -214,7 +214,7 @@ describe('runBackupVerify (T10319 core SDK)', () => {
     expect(result.summary.corrupt).toBeGreaterThanOrEqual(1);
   });
 
-  it('detects 3-DB mixed fixture: fresh+healthy / stale+healthy / corrupt', () => {
+  it('detects 3-DB mixed fixture: fresh+healthy / stale brain covered by the project snapshot / corrupt', () => {
     // 1. Fresh + healthy: tasks
     const now = new Date();
     const stampNow = `${now.getFullYear()}${String(now.getMonth() + 1).padStart(2, '0')}${String(now.getDate()).padStart(2, '0')}-${String(now.getHours()).padStart(2, '0')}${String(now.getMinutes()).padStart(2, '0')}${String(now.getSeconds()).padStart(2, '0')}`;
@@ -241,14 +241,15 @@ describe('runBackupVerify (T10319 core SDK)', () => {
     });
 
     expect(result.dbs['tasks']?.verdict).toBe('healthy');
-    expect(result.dbs['brain']?.verdict).toBe('stale');
+    // T13891: the fresh tasks-* snapshot is the whole project store, so it is
+    // brain's freshest snapshot too; the 48h brain-* copy no longer decides.
+    expect(result.dbs['brain']?.verdict).toBe('healthy');
     expect(result.dbs['conduit']?.verdict).toBe('corrupt');
 
     // Summary must add up across all roles.
     const { healthy, stale, corrupt, missing } = result.summary;
     expect(healthy + stale + corrupt + missing).toBe(DB_INVENTORY.length);
-    expect(healthy).toBeGreaterThanOrEqual(1);
-    expect(stale).toBeGreaterThanOrEqual(1);
+    expect(healthy).toBeGreaterThanOrEqual(2);
     expect(corrupt).toBeGreaterThanOrEqual(1);
   });
 

packages/core/src/store/__tests__/backup-store-roundtrip.test.ts

@@ -144,6 +144,30 @@ describe('backups restore onto the live cleo.db (T13245)', () => {
     expect(readFileSync(decoy, 'utf8')).toBe('decoy');
   });
 
+  it.each([
+    'brain',
+    'conduit',
+  ])('backup recover %s picks a newer tasks-* project snapshot over an older %s-* file (T13897)', async (role) => {
+    // An older role-prefixed file (pre-T13891), then the store moves on and a
+    // run writes the one unified project snapshot as tasks-*.
+    const older = sessionSnapshot(role, '20261005-090000');
+    await seedTasks(env.accessor, [
+      { id: 'T003', title: 'after the older snapshot', type: 'task' },
+    ]);
+    const newer = sessionSnapshot('tasks', '20261005-100000');
+    const backedUp = fingerprint(newer);
+    expect(backedUp).not.toEqual(fingerprint(older));
+    await seedTasks(env.accessor, [
+      { id: 'T004', title: 'after the newer snapshot', type: 'task' },
+    ]);
+    resetDbState();
+
+    const result = await recoverProjectStore({ role, projectRoot: env.tempDir, cwd: env.tempDir });
+    expect(result.restored).toBe(true);
+    expect(result.source.path).toBe(newer);
+    expect(fingerprint(live)).toEqual(backedUp);
+  });
+
   it('a corrupt newest snapshot is skipped for the next valid one', async () => {
     const older = sessionSnapshot('tasks', '20261005-090000');
     const backedUp = fingerprint(older);

packages/core/src/store/__tests__/recover-brain-db.test.ts

@@ -204,6 +204,32 @@ describe('recoverMalformedBrainDb (T10303)', () => {
     expect(result.observationsRecovered).toBe(9);
   });
 
+  it('picks a newer tasks-* project snapshot over an older brain-* one (T13897)', () => {
+    const root = mkdtempSync(join(tmpdir(), 'cleo-test-recover-tasks-prefix-'));
+    const cleoDir = join(root, '.cleo');
+    const vacuumDir = join(cleoDir, 'backups', 'sqlite');
+    const snapshotDir = join(cleoDir, 'backups', 'snapshot');
+    const corruptPath = join(cleoDir, 'brain.db');
+    mkdirSync(vacuumDir, { recursive: true });
+    mkdirSync(snapshotDir, { recursive: true });
+
+    seedHealthyBrainDb(join(vacuumDir, 'brain-20260523-120000.db'), 2);
+    const newer = join(vacuumDir, 'tasks-20260523-131622.db');
+    seedHealthyBrainDb(newer, 5);
+    writeCorruptFile(corruptPath);
+
+    const result = recoverMalformedBrainDb({
+      corruptPath,
+      snapshotDir,
+      vacuumSnapshotDir: vacuumDir,
+      logger: makeLogger(),
+    });
+
+    expect(result.integrityOK).toBe(true);
+    expect(result.restoredFrom).toBe(newer);
+    expect(result.observationsRecovered).toBe(5);
+  });
+
   it('uses legacy PRE-DUP-FIX artifacts as a last-resort fallback', () => {
     const root = mkdtempSync(join(tmpdir(), 'cleo-test-recover-predup-'));
     const cleoDir = join(root, '.cleo');

packages/core/src/store/__tests__/sqlite-backup-real-process.test.ts

@@ -13,10 +13,11 @@
  * 3. Invokes `vacuumIntoBackupAll({ cwd: tempDir })`.
  * 4. Exits cleanly.
  *
- * The parent process then asserts that a `brain-YYYYMMDD-HHmmss.db` file
- * landed in `<tempDir>/.cleo/backups/sqlite/`. Before the T10316 fix the
- * fast-path returned `null` and snapshotOne silently skipped brain — so
- * the only artifacts were `tasks-*.db` snapshots.
+ * The parent process then asserts the snapshot landed in
+ * `<tempDir>/.cleo/backups/sqlite/`. Before the T10316 fix the fast-path
+ * returned `null` and snapshotOne silently skipped brain. Since T13891 brain
+ * lives in the unified project cleo.db, so the run writes ONE `tasks-*.db`
+ * snapshot that holds it, and no separate `brain-*.db` copy.
  *
  * This test deliberately bypasses vitest mocks because the bug surfaces only
  * in a real process where module-singleton caches are empty. The mock-based
@@ -35,6 +36,7 @@ import { tmpdir } from 'node:os';
 import { dirname, join, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+import { collectSnapshotCandidatesForRole } from '../recover-malformed-db.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
@@ -64,7 +66,7 @@ describe('sqlite-backup real-process (T10316)', () => {
     }
   });
 
-  it('produces brain-YYYYMMDD-HHmmss.db even when no caller pre-opened brain.db', () => {
+  it('covers brain in the one project snapshot even when no caller pre-opened brain.db (T10316, T13891)', () => {
     // The compiled dist MUST exist — the test depends on the real module
     // graph (no vitest module mocks). Builds run before tests via the
     // monorepo workflow; a missing dist is a clear signal to rebuild.
@@ -121,12 +123,17 @@ describe('sqlite-backup real-process (T10316)', () => {
     const brainSnapshots = files.filter((f) => /^brain-\d{8}-\d{6}\.db$/.test(f));
     const tasksSnapshots = files.filter((f) => /^tasks-\d{8}-\d{6}\.db$/.test(f));
 
-    // Headline regression check: at LEAST one brain-*.db snapshot file.
-    // Pre-fix, this count was 0 in production despite tasks-*.db being healthy.
-    expect(brainSnapshots.length).toBeGreaterThanOrEqual(1);
+    // T13891: brain lives in the unified project cleo.db, so the run writes
+    // ONE project snapshot (tasks-*) that holds the brain tables, and no
+    // separate brain-*.db or conduit-*.db copy.
+    expect(tasksSnapshots).toHaveLength(1);
+    expect(brainSnapshots).toHaveLength(0);
+    expect(files.filter((f) => /^conduit-\d{8}-\d{6}\.db$/.test(f))).toHaveLength(0);
 
-    // Sanity: tasks snapshot should also exist — confirms the eager-open
-    // contract holds for the previously-working path too.
-    expect(tasksSnapshots.length).toBeGreaterThanOrEqual(1);
+    // Recovery finds that snapshot for brain and conduit (T13897).
+    for (const role of ['brain', 'conduit'] as const) {
+      const candidates = collectSnapshotCandidatesForRole({ role, vacuumSnapshotDir: backupDir });
+      expect(candidates.map((c) => c.path)).toEqual([join(backupDir, tasksSnapshots[0] ?? '')]);
+    }
   });
 });

packages/core/src/store/__tests__/sqlite-backup.test.ts

@@ -19,7 +19,7 @@
  * @epic T4867
  */
 
-import { chmodSync, mkdirSync, readdirSync, statSync, utimesSync, writeFileSync } from 'node:fs';
+import { chmodSync, mkdirSync, readdirSync, utimesSync, writeFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { DatabaseSync } from 'node:sqlite';
@@ -415,7 +415,13 @@ describe('sqlite-backup', () => {
       'tasks-20260102-120000.db',
       'tasks-20260101-120000.db',
     ]);
-    expect(brainList.map((e) => e.name)).toEqual(['brain-20260103-120000.db']);
+    // T13891: brain lives in the unified store, so its listing holds the
+    // project snapshots (tasks-*) plus older brain-* files, newest first.
+    expect(brainList.map((e) => e.name)).toEqual([
+      'brain-20260103-120000.db',
+      'tasks-20260102-120000.db',
+      'tasks-20260101-120000.db',
+    ]);
     // T10317: every project-tier + derived inventory row now contributes a
     // bucket to listSqliteBackupsAll(). Empty buckets surface as `[]`.
     expect(Object.keys(all).sort()).toEqual(
@@ -599,11 +605,12 @@ describe('sqlite-backup', () => {
   });
 
   /**
-   * T12508 #2: tasks, brain and conduit share ONE cleo.db handle. A run must
-   * VACUUM it once and hard-link the same file under the other prefixes, so
-   * every `<prefix>-*.db` reader still finds a file at no extra disk cost.
+   * T12508 #2 / T13891: tasks, brain and conduit share ONE cleo.db handle. A
+   * run VACUUMs it once and writes ONE project snapshot; brain and conduit are
+   * covered by that file (no hard link, no copy), so a session end costs one
+   * copy of the store, not three under per-prefix retention.
    */
-  it('one VACUUM per physical database file; other prefixes are hard links (T12508)', async () => {
+  it('one project snapshot per run for the unified store; brain and conduit are covered by it (T12508, T13891)', async () => {
     const tempDir = join(tmpdir(), `cleo-t12508-dedupe-${Date.now()}`);
     const backupDir = join(tempDir, 'backups', 'sqlite');
     mkdirSync(tempDir, { recursive: true });
@@ -639,17 +646,17 @@ describe('sqlite-backup', () => {
     expect(r?.snapshotted).toEqual(['tasks', 'brain', 'conduit']);
     expect(r?.linked).toEqual(['brain', 'conduit']);
     const files = readdirSync(backupDir).filter((f) => /^(tasks|brain|conduit)-/.test(f));
-    expect(files).toHaveLength(3);
-    const inodes = new Set(files.map((f) => statSync(join(backupDir, f)).ino));
-    expect(inodes.size).toBe(1);
+    expect(files).toHaveLength(1);
+    expect(files[0]).toMatch(/^tasks-\d{8}-\d{6}\.db$/);
   });
 
   /**
-   * T12508: on a filesystem without hard links (exFAT → ENOTSUP) the shared
-   * file is COPIED under the other prefixes instead — still one VACUUM, and
-   * `brain-*` / `conduit-*` still exist for restore and recovery.
+   * T13891: on a filesystem without hard links (exFAT → ENOTSUP) the old
+   * design COPIED the shared file under brain and conduit (three full copies
+   * per session end). Now nothing is linked or copied: one file, and
+   * `listBrainBackups` finds the brain tables in that project snapshot.
    */
-  it('falls back to a copy when hard links are unsupported (T12508)', async () => {
+  it('writes one project snapshot, never a copy, where hard links are unsupported (T13891)', async () => {
     const tempDir = join(tmpdir(), `cleo-t12508-nolink-${Date.now()}`);
     const backupDir = join(tempDir, 'backups', 'sqlite');
     mkdirSync(tempDir, { recursive: true });
@@ -696,13 +703,12 @@ describe('sqlite-backup', () => {
 
     expect(vacuums).toBe(1);
     expect(r?.failed).toEqual([]);
-    expect(r?.linked).toEqual([]);
+    expect(r?.linked).toEqual(['brain', 'conduit']);
     expect(r?.snapshotted).toEqual(['tasks', 'brain', 'conduit']);
     const files = readdirSync(backupDir).filter((f) => /^(tasks|brain|conduit)-.*\.db$/.test(f));
-    expect(files).toHaveLength(3);
-    // Three separate files (copies), and brain recovery finds its prefix.
-    expect(new Set(files.map((f) => statSync(join(backupDir, f)).ino)).size).toBe(3);
-    expect(brainList).toHaveLength(1);
+    expect(files).toHaveLength(1);
+    // The one project snapshot is what the brain listing returns.
+    expect(brainList.map((e) => e.name)).toEqual(files);
   });
 
   /**

packages/core/src/store/backup-recover.ts

@@ -38,6 +38,7 @@ import {
   recoverMalformedDb,
   resolveRoleBackupDirs,
   resolveRoleDbPath,
+  vacuumSnapshotPrefixes,
 } from './recover-malformed-db.js';
 import { ensureTriggerSuspendTableAtPath } from './sync/trigger-suspend-at-path.js';
 import {
@@ -215,11 +216,13 @@ function snapshotMatchesPin(role: DbRole, candidate: SnapshotCandidate, pin: str
     );
     if (iso.startsWith(pin)) return true;
   }
-  // Vacuum snapshot: `<role>-20260523-130026.db`.
-  const vacuumPrefix = `${role}-`;
-  if (name.startsWith(vacuumPrefix) && name.endsWith('.db')) {
-    const tail = name.slice(vacuumPrefix.length, -3); // strip ".db"
-    if (tail.startsWith(pin)) return true;
+  // Vacuum snapshot: `<prefix>-20260523-130026.db` (`tasks-*` also holds brain and conduit, T13897).
+  for (const prefix of vacuumSnapshotPrefixes(role)) {
+    const vacuumPrefix = `${prefix}-`;
+    if (name.startsWith(vacuumPrefix) && name.endsWith('.db')) {
+      const tail = name.slice(vacuumPrefix.length, -3); // strip ".db"
+      if (tail.startsWith(pin)) return true;
+    }
   }
   return false;
 }

packages/core/src/store/backup-verify.ts

@@ -141,8 +141,11 @@ function buildSnapshotPatterns(role: string): readonly RegExp[] {
     new RegExp(`^${safe}\\.db\\.[A-Za-z0-9_-]+-\\d{8}-\\d{6}$`),
     new RegExp(`^${safe}\\.db\\.snapshot-\\d{4}-\\d{2}-\\d{2}T\\d{2}-\\d{2}-\\d{2}-\\d{3}Z$`),
     // T13245: `createBackup` writes ONE `cleo.db.<backupId>` copy of the
-    // project store, which holds the tasks, brain and conduit tables.
-    ...(PROJECT_STORE_LABEL_ROLES.has(role) ? [/^cleo\.db\.[A-Za-z0-9_-]+-\d{8}-\d{6}$/] : []),
+    // project store, which holds the tasks, brain and conduit tables. T13891:
+    // `vacuumIntoBackupAll` likewise writes one `tasks-*.db` for all three.
+    ...(PROJECT_STORE_LABEL_ROLES.has(role)
+      ? [/^cleo\.db\.[A-Za-z0-9_-]+-\d{8}-\d{6}$/, /^tasks-\d{8}-\d{6}\.db$/]
+      : []),
   ];
 }
 

packages/core/src/store/recover-brain-db.ts

@@ -138,9 +138,11 @@ const SNAPSHOT_FILENAME_RE = /^brain\.db\.snapshot-(\d{4}-\d{2}-\d{2}T\d{2}-\d{2
 
 /**
  * Snapshot filename pattern for VACUUM INTO debounced session-end snapshots:
- * `brain-20260523-130026.db`. Format mirrors `sqlite-backup.ts:formatTimestamp`.
+ * `brain-20260523-130026.db`, and `tasks-*.db`: brain lives in the unified
+ * project store, whose one snapshot per run carries the tasks prefix
+ * (T13891, T13897). Format mirrors `sqlite-backup.ts:formatTimestamp`.
  */
-const VACUUM_FILENAME_RE = /^brain-(\d{8})-(\d{6})\.db$/;
+const VACUUM_FILENAME_RE = /^(?:brain|tasks)-(\d{8})-(\d{6})\.db$/;
 
 /** Legacy pre-T9685 dup-fix backup pattern: `brain.db.PRE-DUP-FIX-191315`. */
 const PRE_DUP_FIX_RE = /^brain\.db\.PRE-DUP-FIX-/;

packages/core/src/store/recover-malformed-db.ts

@@ -255,14 +255,29 @@ function buildSystemSnapshotRegex(role: DbRole): RegExp {
   );
 }
 
+/**
+ * VACUUM INTO filename prefixes that hold a role's data. Brain and conduit
+ * live in the unified project `cleo.db`, whose one snapshot per run is
+ * `tasks-*.db` (T13891); older runs also wrote `brain-*` / `conduit-*`.
+ *
+ * @param role - Inventory role.
+ * @returns The prefixes whose `<prefix>-YYYYMMDD-HHmmss.db` files hold it.
+ * @task T13897
+ */
+export function vacuumSnapshotPrefixes(role: DbRole): readonly string[] {
+  return role === 'brain' || role === 'conduit' ? [role, 'tasks'] : [role];
+}
+
 /**
  * Build the per-role VACUUM-INTO snapshot filename regex (matches
- * `<role>-20260523-130026.db`).
+ * `<prefix>-20260523-130026.db` for every {@link vacuumSnapshotPrefixes}
+ * prefix, so the freshest is picked across them).
  *
  * @internal
  */
 function buildVacuumSnapshotRegex(role: DbRole): RegExp {
-  return new RegExp(`^${escapeRegExpLiteral(role)}-(\\d{8})-(\\d{6})\\.db$`);
+  const prefixes = vacuumSnapshotPrefixes(role).map(escapeRegExpLiteral).join('|');
+  return new RegExp(`^(?:${prefixes})-(\\d{8})-(\\d{6})\\.db$`);
 }
 
 /**