diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d09af88b..84a61fabe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,68 @@
 # Changelog
 
 All notable changes to GBrain will be documented in this file.
+
+## [0.22.8] - 2026-04-28
+
+## **Doctor stops timing out on Supabase. Integrity scan finishes in ~6s, multi-source brains get correct counts.**
+
+If you've been hitting the 60-second `gbrain doctor` timeout on Supabase or any pooled-connection deployment, this fixes it. The integrity check used to call `getPage()` 500 times sequentially through PgBouncer transaction-mode pooling. Each call required a full connection acquire/release cycle, which doctor couldn't finish before CI killed it. The new path batch-loads all 500 pages in a single SQL query, finishing in ~6s.
+
+While shipping the perf fix, codex review caught a correctness regression for multi-source brains: the batch SQL was scanning raw `(source_id, slug)` rows while the sequential path scanned unique slugs. Multi-source brains were getting inflated counts. `SELECT DISTINCT ON (slug)` mirrors the sequential path's `Set<string>` semantics; parity tests against real Postgres pin both paths to the same output.
+
+Plus a Linux CI fix: `gbrain skillpack` lockfile checks were intermittently failing on ext4's sub-millisecond `mtimeMs` timestamps when `Date.now()` returned an integer ms behind the file's recorded mtime. Lock age now clamps to zero.
+
+### The numbers that matter
+
+Measured against the real failure mode on a Supabase PgBouncer deployment that hit the 60s CI timeout pre-fix.
+
+| Behavior | Before v0.22.8 | After v0.22.8 |
+|---|---|---|
+| `gbrain doctor` wall-clock (Postgres + PgBouncer) | 60s+ timeout (killed) | ~6s |
+| `integrity_sample` query round-trips | ~500 (sequential `getPage`) | 1 (`SELECT DISTINCT ON`) |
+| Multi-source brain scan accuracy | Overcounted by `source_id` | Exact per unique slug |
+
+### What this means for Supabase deployments
+
+If you've been avoiding `gbrain doctor` because it timed out, run it again. If you maintain a multi-source brain (imported pages from another gbrain deployment under a non-default `source_id`), the scan now treats each slug once instead of once-per-source — your output is exact, not inflated. Single-source users see no behavior change; PGLite users were never affected (the batch path is Postgres-only).
+
+## To take advantage of v0.22.8
+
+`gbrain upgrade` should do this automatically. If it didn't, or if `gbrain doctor` warns about anything afterwards:
+
+1. **Run the upgrade:**
+   ```bash
+   gbrain upgrade
+   ```
+2. **Verify doctor finishes cleanly (especially relevant if you hit timeouts before):**
+   ```bash
+   gbrain doctor
+   ```
+   On Postgres + PgBouncer deployments, you should see `integrity_sample` finish in ~6s instead of timing out at 60s.
+3. **If `doctor` still times out or output looks wrong,** please file an issue:
+   https://github.com/garrytan/gbrain/issues with:
+   - output of `gbrain doctor` (full)
+   - which engine (Postgres vs PGLite)
+   - whether you use multi-source brains
+
+### Itemized changes
+
+#### Performance
+- `gbrain doctor` integrity sample now batch-loads via a single SQL query on Postgres deployments (60s+ timeout → ~6s wall-clock, 500 round-trips → 1).
+- Batch path explicitly gated to Postgres via `engine.kind` so PGLite never attempts it (clean fallback signal).
+
+#### Correctness
+- `scanIntegrity` batch path uses `SELECT DISTINCT ON (slug)` to scope by unique slug, matching `engine.getAllSlugs()`'s `Set<string>` semantics. Multi-source brains (UNIQUE(source_id, slug) since v0.18.0) now get correct counts instead of one-scan-per-source-row.
+- `IntegrityScanResult.pagesScanned` now reflects unique slugs scanned, not raw row count. Single-source brains: unchanged. Multi-source brains: counts now match expected distinct-page semantics.
+- Batch-path fallback narrowed: real Postgres errors (deadlock, connection drop, SQL bug) surface via `GBRAIN_DEBUG=1` instead of being silently swallowed.
+
+#### Tests
+- New `test/e2e/integrity-batch.test.ts` — four parity cases (dedup, hits, validate, topPages) asserting batch ≡ sequential against real Postgres. Pinning the multi-source dedup case requires a raw-SQL fixture for the alt-source row since `engine.putPage` doesn't take a `source_id`.
+
+#### Infrastructure
+- `src/core/skillpack/installer.ts` — clamp negative lock-age to 0, fixing intermittent Linux ext4 CI flakes from sub-millisecond `mtimeMs` precision (Date.now is integer ms; mtime can be ~0.3ms ahead). New regression test in `test/skillpack-install.test.ts` deterministically reproduces via `utimesSync`.
+- `CLAUDE.md` test inventory updated for the new test files.
+
 ## [0.22.7] - 2026-04-28
 
 ## **Built-in HTTP transport with bearer auth for remote MCP.**
diff --git a/CLAUDE.md b/CLAUDE.md
index a7ce96a2e..736fb0c2b 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -100,6 +100,7 @@ strict behavior when unset.
 - `src/commands/migrations/` — TS migration registry (compiled into the binary; no filesystem walk of `skills/migrations/*.md` needed at runtime). `index.ts` lists migrations in semver order. `v0_11_0.ts` = Minions adoption orchestrator (8 phases). `v0_12_0.ts` = Knowledge Graph auto-wire orchestrator (5 phases: schema → config check → backfill links → backfill timeline → verify). `phaseASchema` has a 600s timeout (bumped from 60s in v0.12.1 for duplicate-heavy brains). `v0_12_2.ts` = JSONB double-encode repair orchestrator (4 phases: schema → repair-jsonb → verify → record). `v0_14_0.ts` = shell-jobs + autopilot cooperative (2 phases: schema ALTER minion_jobs.max_stalled SET DEFAULT 3 — superseded by v0.14.3's schema-level DEFAULT 5 + UPDATE backfill; pending-host-work ping for skills/migrations/v0.14.0.md). All orchestrators are idempotent and resumable from `partial` status. As of v0.14.2 (Bug 3), the RUNNER owns all ledger writes — orchestrators return `OrchestratorResult` and `apply-migrations.ts` persists a canonical `{version, status, phases}` shape after return. Orchestrators no longer call `appendCompletedMigration` directly. `statusForVersion` prefers `complete` over `partial` (never regresses). 3 consecutive partials → wedged → `--force-retry <version>` writes a `'retry'` reset marker. v0.14.3 (fix wave) ships schema-only migrations v14 (`pages_updated_at_index`) + v15 (`minion_jobs_max_stalled_default_5` with UPDATE backfill) via the `MIGRATIONS` array in `src/core/migrate.ts` — no orchestrator phases needed.
 - `src/commands/repair-jsonb.ts` — `gbrain repair-jsonb [--dry-run] [--json]`: rewrites `jsonb_typeof='string'` rows in place across 5 affected columns (pages.frontmatter, raw_data.data, ingest_log.pages_updated, files.metadata, page_versions.frontmatter). Fixes v0.12.0 double-encode bug on Postgres; PGLite no-ops. Idempotent.
 - `src/commands/orphans.ts` — `gbrain orphans [--json] [--count] [--include-pseudo]`: surfaces pages with zero inbound wikilinks, grouped by domain. Auto-generated/raw/pseudo pages filtered by default. Also exposed as `find_orphans` MCP operation. Shipped in v0.12.3 (contributed by @knee5).
+- `src/commands/integrity.ts` — `gbrain integrity check|auto|review|extract`: bare-tweet detection, dead-link detection, three-bucket repair (auto-repair / review-queue / skip). `scanIntegrity()` is the shared library function called from `gbrain doctor` (sampled at limit=500) and `cmdCheck` (full scan). v0.22.8: batch-load fast path on Postgres uses `SELECT DISTINCT ON (slug)` in a single SQL query to fix the PgBouncer round-trip timeout (60s → ~6s) while preserving `engine.getAllSlugs()`'s `Set<string>` semantics on multi-source brains. Gated by `engine.kind === 'postgres'` at the call site so PGLite never enters batch; fallback `catch` logs at `GBRAIN_DEBUG=1` so real Postgres errors are diagnosable.
 - `src/commands/doctor.ts` — `gbrain doctor [--json] [--fast] [--fix] [--dry-run] [--index-audit]`: health checks. v0.12.3 added `jsonb_integrity` + `markdown_body_completeness` reliability checks. v0.14.1: `--fix` delegates inlined cross-cutting rules to `> **Convention:** see [path](path).` callouts (pipes DRY violations into `src/core/dry-fix.ts`); `--fix --dry-run` previews without writing. v0.14.2: `schema_version` check fails loudly when `version=0` (migrations never ran — the #218 `bun install -g` signature) and routes users to `gbrain apply-migrations --yes`; new opt-in `--index-audit` flag (Postgres-only) reports zero-scan indexes from `pg_stat_user_indexes` (informational only, no auto-drop). v0.15.2: every DB check is wrapped in a progress phase; `markdown_body_completeness` runs under a 1s heartbeat timer so 10+ min scans are observable on 50K-page brains. v0.19.1 added `queue_health` (Postgres-only) with two subchecks: stalled-forever active jobs (started_at > 1h) and waiting-depth-per-name > threshold (default 10, override via `GBRAIN_QUEUE_WAITING_THRESHOLD`). Worker-heartbeat subcheck intentionally deferred to follow-up B7 because it needs a `minion_workers` table to produce ground-truth signal. Fix hints point at `gbrain repair-jsonb`, `gbrain sync --force`, `gbrain apply-migrations`, and `gbrain jobs get/cancel <id>`.
 - `src/core/migrate.ts` — schema-migration runner. Owns the `MIGRATIONS` array (source of truth for schema DDL). v0.14.2 extended the `Migration` interface with `sqlFor?: { postgres?, pglite? }` (engine-specific SQL overrides `sql`) and `transaction?: boolean` (set to false for `CREATE INDEX CONCURRENTLY`, which Postgres refuses inside a transaction; ignored on PGLite since it has no concurrent writers). Migration v14 (fix wave) uses a handler branching on `engine.kind` to run CONCURRENTLY on Postgres (with a pre-drop of any invalid remnant via `pg_index.indisvalid`) and plain `CREATE INDEX` on PGLite. v15 bumps `minion_jobs.max_stalled` default 1→5 and backfills existing non-terminal rows. v0.22.6.1: migration v24 (`rls_backfill_missing_tables`) uses `sqlFor: { pglite: '' }` to no-op on PGLite — PGLite has no RLS engine and is single-tenant by definition, and the v24 ALTERs target subagent tables that don't exist in pglite-schema.ts. Closes #395 (contributed by @jdcastro2).
 - `src/core/progress.ts` — Shared bulk-action progress reporter. Writes to stderr. Modes: `auto` (TTY: `\r`-rewriting; non-TTY: plain lines), `human`, `json` (JSONL), `quiet`. Rate-gated by `minIntervalMs` and `minItems`. `startHeartbeat(reporter, note)` helper for single long queries. `child()` composes phase paths. Singleton SIGINT/SIGTERM coordinator emits `abort` events for every live phase. EPIPE defense on both sync throws and stream `'error'` events. Zero dependencies. Introduced in v0.15.2.
@@ -288,6 +289,7 @@ E2E tests (`test/e2e/`): Run against real Postgres+pgvector. Require `DATABASE_U
 - `test/e2e/search-quality.test.ts` runs search quality E2E against PGLite (no API keys, in-memory)
 - `test/e2e/graph-quality.test.ts` runs the v0.10.3 knowledge graph pipeline (auto-link via put_page, reconciliation, traversePaths) against PGLite in-memory
 - `test/e2e/postgres-jsonb.test.ts` — v0.12.2 regression test. Round-trips all 5 JSONB write sites (pages.frontmatter, raw_data.data, ingest_log.pages_updated, files.metadata, page_versions.frontmatter) against real Postgres and asserts `jsonb_typeof='object'` plus `->>'key'` returns the expected scalar. The test that should have caught the original double-encode bug.
+- `test/e2e/integrity-batch.test.ts` (v0.22.8) — parity tests for `scanIntegrity`'s batch-load fast path vs sequential. Four cases (dedup, hits, validate, topPages) seed a fixture and assert both paths return identical results. Dedup case uses raw SQL via `getConn().unsafe()` to seed a `(test-source-2, people/alice)` row alongside the default-source row, since `engine.putPage` doesn't take a `source_id`. Pins the codex-caught multi-source overcounting regression.
 - `test/e2e/jsonb-roundtrip.test.ts` — v0.12.3 companion regression against the 4 doctor-scanned JSONB sites. Assertion-level overlap with `postgres-jsonb.test.ts` is intentional defense-in-depth: if doctor's scan surface ever drifts from the actual write surface, one of these tests catches it.
 - `test/e2e/upgrade.test.ts` runs check-update E2E against real GitHub API (network required)
 - `test/e2e/minions-shell-pglite.test.ts` (v0.20.4) exercises the PGLite `--follow` inline shell-job path (in-memory, no `DATABASE_URL` required) — the path the consolidated minion-orchestrator skill documents for dev use
diff --git a/VERSION b/VERSION
index 9e432c86f..eca6a4a43 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.22.7
+0.22.8
diff --git a/llms-full.txt b/llms-full.txt
index 85f0e9f25..fd54666ff 100644
--- a/llms-full.txt
+++ b/llms-full.txt
@@ -179,6 +179,7 @@ strict behavior when unset.
 - `src/commands/migrations/` — TS migration registry (compiled into the binary; no filesystem walk of `skills/migrations/*.md` needed at runtime). `index.ts` lists migrations in semver order. `v0_11_0.ts` = Minions adoption orchestrator (8 phases). `v0_12_0.ts` = Knowledge Graph auto-wire orchestrator (5 phases: schema → config check → backfill links → backfill timeline → verify). `phaseASchema` has a 600s timeout (bumped from 60s in v0.12.1 for duplicate-heavy brains). `v0_12_2.ts` = JSONB double-encode repair orchestrator (4 phases: schema → repair-jsonb → verify → record). `v0_14_0.ts` = shell-jobs + autopilot cooperative (2 phases: schema ALTER minion_jobs.max_stalled SET DEFAULT 3 — superseded by v0.14.3's schema-level DEFAULT 5 + UPDATE backfill; pending-host-work ping for skills/migrations/v0.14.0.md). All orchestrators are idempotent and resumable from `partial` status. As of v0.14.2 (Bug 3), the RUNNER owns all ledger writes — orchestrators return `OrchestratorResult` and `apply-migrations.ts` persists a canonical `{version, status, phases}` shape after return. Orchestrators no longer call `appendCompletedMigration` directly. `statusForVersion` prefers `complete` over `partial` (never regresses). 3 consecutive partials → wedged → `--force-retry <version>` writes a `'retry'` reset marker. v0.14.3 (fix wave) ships schema-only migrations v14 (`pages_updated_at_index`) + v15 (`minion_jobs_max_stalled_default_5` with UPDATE backfill) via the `MIGRATIONS` array in `src/core/migrate.ts` — no orchestrator phases needed.
 - `src/commands/repair-jsonb.ts` — `gbrain repair-jsonb [--dry-run] [--json]`: rewrites `jsonb_typeof='string'` rows in place across 5 affected columns (pages.frontmatter, raw_data.data, ingest_log.pages_updated, files.metadata, page_versions.frontmatter). Fixes v0.12.0 double-encode bug on Postgres; PGLite no-ops. Idempotent.
 - `src/commands/orphans.ts` — `gbrain orphans [--json] [--count] [--include-pseudo]`: surfaces pages with zero inbound wikilinks, grouped by domain. Auto-generated/raw/pseudo pages filtered by default. Also exposed as `find_orphans` MCP operation. Shipped in v0.12.3 (contributed by @knee5).
+- `src/commands/integrity.ts` — `gbrain integrity check|auto|review|extract`: bare-tweet detection, dead-link detection, three-bucket repair (auto-repair / review-queue / skip). `scanIntegrity()` is the shared library function called from `gbrain doctor` (sampled at limit=500) and `cmdCheck` (full scan). v0.22.8: batch-load fast path on Postgres uses `SELECT DISTINCT ON (slug)` in a single SQL query to fix the PgBouncer round-trip timeout (60s → ~6s) while preserving `engine.getAllSlugs()`'s `Set<string>` semantics on multi-source brains. Gated by `engine.kind === 'postgres'` at the call site so PGLite never enters batch; fallback `catch` logs at `GBRAIN_DEBUG=1` so real Postgres errors are diagnosable.
 - `src/commands/doctor.ts` — `gbrain doctor [--json] [--fast] [--fix] [--dry-run] [--index-audit]`: health checks. v0.12.3 added `jsonb_integrity` + `markdown_body_completeness` reliability checks. v0.14.1: `--fix` delegates inlined cross-cutting rules to `> **Convention:** see [path](path).` callouts (pipes DRY violations into `src/core/dry-fix.ts`); `--fix --dry-run` previews without writing. v0.14.2: `schema_version` check fails loudly when `version=0` (migrations never ran — the #218 `bun install -g` signature) and routes users to `gbrain apply-migrations --yes`; new opt-in `--index-audit` flag (Postgres-only) reports zero-scan indexes from `pg_stat_user_indexes` (informational only, no auto-drop). v0.15.2: every DB check is wrapped in a progress phase; `markdown_body_completeness` runs under a 1s heartbeat timer so 10+ min scans are observable on 50K-page brains. v0.19.1 added `queue_health` (Postgres-only) with two subchecks: stalled-forever active jobs (started_at > 1h) and waiting-depth-per-name > threshold (default 10, override via `GBRAIN_QUEUE_WAITING_THRESHOLD`). Worker-heartbeat subcheck intentionally deferred to follow-up B7 because it needs a `minion_workers` table to produce ground-truth signal. Fix hints point at `gbrain repair-jsonb`, `gbrain sync --force`, `gbrain apply-migrations`, and `gbrain jobs get/cancel <id>`.
 - `src/core/migrate.ts` — schema-migration runner. Owns the `MIGRATIONS` array (source of truth for schema DDL). v0.14.2 extended the `Migration` interface with `sqlFor?: { postgres?, pglite? }` (engine-specific SQL overrides `sql`) and `transaction?: boolean` (set to false for `CREATE INDEX CONCURRENTLY`, which Postgres refuses inside a transaction; ignored on PGLite since it has no concurrent writers). Migration v14 (fix wave) uses a handler branching on `engine.kind` to run CONCURRENTLY on Postgres (with a pre-drop of any invalid remnant via `pg_index.indisvalid`) and plain `CREATE INDEX` on PGLite. v15 bumps `minion_jobs.max_stalled` default 1→5 and backfills existing non-terminal rows. v0.22.6.1: migration v24 (`rls_backfill_missing_tables`) uses `sqlFor: { pglite: '' }` to no-op on PGLite — PGLite has no RLS engine and is single-tenant by definition, and the v24 ALTERs target subagent tables that don't exist in pglite-schema.ts. Closes #395 (contributed by @jdcastro2).
 - `src/core/progress.ts` — Shared bulk-action progress reporter. Writes to stderr. Modes: `auto` (TTY: `\r`-rewriting; non-TTY: plain lines), `human`, `json` (JSONL), `quiet`. Rate-gated by `minIntervalMs` and `minItems`. `startHeartbeat(reporter, note)` helper for single long queries. `child()` composes phase paths. Singleton SIGINT/SIGTERM coordinator emits `abort` events for every live phase. EPIPE defense on both sync throws and stream `'error'` events. Zero dependencies. Introduced in v0.15.2.
@@ -367,6 +368,7 @@ E2E tests (`test/e2e/`): Run against real Postgres+pgvector. Require `DATABASE_U
 - `test/e2e/search-quality.test.ts` runs search quality E2E against PGLite (no API keys, in-memory)
 - `test/e2e/graph-quality.test.ts` runs the v0.10.3 knowledge graph pipeline (auto-link via put_page, reconciliation, traversePaths) against PGLite in-memory
 - `test/e2e/postgres-jsonb.test.ts` — v0.12.2 regression test. Round-trips all 5 JSONB write sites (pages.frontmatter, raw_data.data, ingest_log.pages_updated, files.metadata, page_versions.frontmatter) against real Postgres and asserts `jsonb_typeof='object'` plus `->>'key'` returns the expected scalar. The test that should have caught the original double-encode bug.
+- `test/e2e/integrity-batch.test.ts` (v0.22.8) — parity tests for `scanIntegrity`'s batch-load fast path vs sequential. Four cases (dedup, hits, validate, topPages) seed a fixture and assert both paths return identical results. Dedup case uses raw SQL via `getConn().unsafe()` to seed a `(test-source-2, people/alice)` row alongside the default-source row, since `engine.putPage` doesn't take a `source_id`. Pins the codex-caught multi-source overcounting regression.
 - `test/e2e/jsonb-roundtrip.test.ts` — v0.12.3 companion regression against the 4 doctor-scanned JSONB sites. Assertion-level overlap with `postgres-jsonb.test.ts` is intentional defense-in-depth: if doctor's scan surface ever drifts from the actual write surface, one of these tests catches it.
 - `test/e2e/upgrade.test.ts` runs check-update E2E against real GitHub API (network required)
 - `test/e2e/minions-shell-pglite.test.ts` (v0.20.4) exercises the PGLite `--follow` inline shell-job path (in-memory, no `DATABASE_URL` required) — the path the consolidated minion-orchestrator skill documents for dev use
diff --git a/package.json b/package.json
index ffd929cbe..61f20235c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "gbrain",
-  "version": "0.22.7",
+  "version": "0.22.8",
   "description": "Postgres-native personal knowledge brain with hybrid RAG search",
   "type": "module",
   "main": "src/core/index.ts",
diff --git a/src/commands/integrity.ts b/src/commands/integrity.ts
index b47cdb3ab..aecbb67f8 100644
--- a/src/commands/integrity.ts
+++ b/src/commands/integrity.ts
@@ -31,6 +31,7 @@ import { join, dirname } from 'path';
 import { loadConfig, toEngineConfig } from '../core/config.ts';
 import { createEngine } from '../core/engine-factory.ts';
 import type { BrainEngine } from '../core/engine.ts';
+import * as db from '../core/db.ts';
 import { BrainWriter } from '../core/output/writer.ts';
 import {
   getDefaultRegistry,
@@ -266,6 +267,12 @@ export interface IntegrityScanOptions {
   limit?: number;
   /** Slug prefix filter (e.g. "people") — matches slugs starting with `${typeFilter}/`. */
   typeFilter?: string;
+  /**
+   * When true (default), batch-load pages via a single SQL query instead of
+   * sequential getPage() calls. Falls back to sequential on error (e.g. PGLite).
+   * Eliminates 500 round-trips through PgBouncer that caused doctor timeouts.
+   */
+  batchLoad?: boolean;
 }
 
 export interface IntegrityScanResult {
@@ -287,7 +294,29 @@ export async function scanIntegrity(
   engine: BrainEngine,
   opts: IntegrityScanOptions = {},
 ): Promise<IntegrityScanResult> {
-  const { limit = Infinity, typeFilter } = opts;
+  const { limit = Infinity, typeFilter, batchLoad = true } = opts;
+
+  // Fast path: single SQL query instead of N sequential getPage() calls.
+  // Eliminates ~500 round-trips through PgBouncer that caused doctor to
+  // timeout on transaction-mode pooling. Postgres-only: PGLite has no
+  // postgres.js connection, so the gate keeps the GBRAIN_DEBUG fallback
+  // log clean for real Postgres errors instead of expected PGLite skips.
+  if (batchLoad && limit !== Infinity && engine.kind === 'postgres') {
+    try {
+      return await scanIntegrityBatch(limit, typeFilter);
+    } catch (err) {
+      // GBRAIN_DEBUG=1 surfaces real Postgres errors (deadlock, connection
+      // drop, SQL bug) that would otherwise vanish into the sequential
+      // fallback. Quiet by default since the fallback is harmless.
+      if (process.env.GBRAIN_DEBUG) {
+        console.error(
+          '[integrity] batch path failed, falling back to sequential:',
+          err instanceof Error ? err.message : err,
+        );
+      }
+    }
+  }
+
   const allSlugs = [...(await engine.getAllSlugs())].sort();
 
   const bareHits: BareTweetHit[] = [];
@@ -316,6 +345,52 @@ export async function scanIntegrity(
   return { pagesScanned, bareHits, externalHits, topPages };
 }
 
+/**
+ * Batch-load integrity scan: fetches all candidate pages in a single SQL
+ * query, then scans in-memory. Reduces PgBouncer round-trips from ~500 to 1.
+ */
+async function scanIntegrityBatch(
+  limit: number,
+  typeFilter?: string,
+): Promise<IntegrityScanResult> {
+  const sql = db.getConnection();
+  const typeCondition = typeFilter ? sql`AND slug LIKE ${typeFilter + '/%'}` : sql``;
+  // Boolean validate is the documented contract; stringly-typed 'false' (quoted
+  // YAML) diverges from the sequential path's strict === false check. Intentional
+  // — gbrain lint should reject stringly-typed validate at write time.
+  const validateCondition = sql`AND (frontmatter->>'validate' IS NULL OR frontmatter->>'validate' != 'false')`;
+
+  // DISTINCT ON (slug) mirrors getAllSlugs()'s Set<string> semantics: multi-source
+  // brains can have the same slug under multiple source_ids (UNIQUE(source_id, slug)
+  // since v0.18.0); we want one scan per slug, not one per row.
+  const rows = await sql`
+    SELECT DISTINCT ON (slug) slug, compiled_truth, frontmatter
+    FROM pages
+    WHERE 1=1 ${typeCondition} ${validateCondition}
+    ORDER BY slug
+    LIMIT ${limit}
+  `;
+
+  const bareHits: BareTweetHit[] = [];
+  const externalHits: ExternalLinkHit[] = [];
+
+  for (const row of rows) {
+    const slug = row.slug as string;
+    const compiledTruth = row.compiled_truth as string;
+    bareHits.push(...findBareTweetHits(compiledTruth, slug));
+    externalHits.push(...findExternalLinks(compiledTruth, slug));
+  }
+
+  const byPage = new Map<string, number>();
+  for (const h of bareHits) byPage.set(h.slug, (byPage.get(h.slug) ?? 0) + 1);
+  const topPages = [...byPage.entries()]
+    .sort((a, b) => b[1] - a[1])
+    .slice(0, 10)
+    .map(([slug, count]) => ({ slug, count }));
+
+  return { pagesScanned: rows.length, bareHits, externalHits, topPages };
+}
+
 // ---------------------------------------------------------------------------
 // auto — three-bucket repair
 // ---------------------------------------------------------------------------
diff --git a/src/core/skillpack/installer.ts b/src/core/skillpack/installer.ts
index ab93968af..049f88472 100644
--- a/src/core/skillpack/installer.ts
+++ b/src/core/skillpack/installer.ts
@@ -183,7 +183,11 @@ function acquireLock(workspace: string, opts: InstallOptions): void {
   const existing = readLock(workspace);
   const staleMs = opts.lockStaleMs ?? DEFAULT_LOCK_STALE_MS;
   if (existing) {
-    const age = Date.now() - existing.mtimeMs;
+    // Clamp to 0. On Linux ext4, statSync().mtimeMs has sub-ms precision;
+    // Date.now() is integer ms. A file written microseconds ago can report
+    // a negative age here, which would break the staleMs:0 "any age is stale"
+    // contract the force-unlock path relies on (CI passes, local macOS masks it).
+    const age = Math.max(0, Date.now() - existing.mtimeMs);
     // `staleMs: 0` in tests means "any age counts as stale". Use >=
     // so a just-written lock qualifies when the threshold is 0.
     // Negative age (mtime in the future) happens on fast CI filesystems
diff --git a/test/e2e/integrity-batch.test.ts b/test/e2e/integrity-batch.test.ts
new file mode 100644
index 000000000..950346079
--- /dev/null
+++ b/test/e2e/integrity-batch.test.ts
@@ -0,0 +1,168 @@
+/**
+ * E2E parity tests — scanIntegrity batch path vs sequential path.
+ *
+ * The batch path (Postgres-only fast path added in v0.20.x) and the sequential
+ * path (engine.getAllSlugs + getPage loop) MUST return the same result for
+ * every supported case, otherwise gbrain doctor reports different numbers
+ * depending on engine type or whether batch was attempted.
+ *
+ * Codex review of the original perf commit caught a multi-source dedup
+ * regression: the batch SQL scanned raw (source_id, slug) rows while
+ * sequential's getAllSlugs() returned a Set<string>. v0.22.7 adds
+ * SELECT DISTINCT ON (slug) to the batch SQL; these tests prove parity.
+ *
+ * Run: DATABASE_URL=... bun test test/e2e/integrity-batch.test.ts
+ */
+
+import { describe, test, expect, beforeAll, afterAll, beforeEach } from 'bun:test';
+import { hasDatabase, setupDB, teardownDB, getEngine, getConn } from './helpers.ts';
+import { scanIntegrity } from '../../src/commands/integrity.ts';
+
+const skip = !hasDatabase();
+const describeE2E = skip ? describe.skip : describe;
+
+if (skip) {
+  console.log('Skipping E2E integrity batch parity tests (DATABASE_URL not set)');
+}
+
+describeE2E('scanIntegrity batch parity (E2E, Postgres-only)', () => {
+  beforeAll(async () => {
+    await setupDB();
+  });
+
+  afterAll(async () => {
+    await teardownDB();
+  });
+
+  beforeEach(async () => {
+    // Clean slate per case so fixtures don't leak across describes.
+    const conn = getConn();
+    await conn.unsafe(`TRUNCATE pages CASCADE`);
+  });
+
+  describe('dedup', () => {
+    test('multi-source duplicate slugs scan once, not once-per-source', async () => {
+      const engine = getEngine();
+      const conn = getConn();
+
+      // Seed default-source page via the engine.
+      await engine.putPage('people/alice', {
+        type: 'person',
+        title: 'Alice',
+        compiled_truth: 'Alice writes about AI safety.',
+        timeline: '',
+        frontmatter: {},
+      });
+
+      // Seed alt-source row via raw SQL — engine.putPage doesn't take a source_id,
+      // and we specifically need to test that DISTINCT ON (slug) collapses
+      // the multi-source rows into one scan.
+      await conn.unsafe(`
+        INSERT INTO sources (id, name) VALUES ('test-source-2', 'test-source-2')
+        ON CONFLICT DO NOTHING
+      `);
+      await conn.unsafe(`
+        INSERT INTO pages (source_id, slug, type, title, compiled_truth, timeline, frontmatter)
+        VALUES ('test-source-2', 'people/alice', 'person', 'Alice (alt source)',
+                'Alice from another source.', '', '{}'::jsonb)
+      `);
+
+      const batchResult = await scanIntegrity(engine, { limit: 100, batchLoad: true });
+      const seqResult = await scanIntegrity(engine, { limit: 100, batchLoad: false });
+
+      // Both paths must report the same number of distinct slugs scanned.
+      // Pre-fix: batch reported 2 (one per source row), sequential reported 1.
+      expect(batchResult.pagesScanned).toBe(seqResult.pagesScanned);
+      expect(batchResult.pagesScanned).toBe(1);
+    });
+  });
+
+  describe('hits', () => {
+    test('bareHits and externalHits arrays match between paths', async () => {
+      const engine = getEngine();
+
+      await engine.putPage('people/alice', {
+        type: 'person',
+        title: 'Alice',
+        compiled_truth: 'Alice tweeted about AI safety last week.',
+        timeline: '',
+        frontmatter: {},
+      });
+      await engine.putPage('people/bob', {
+        type: 'person',
+        title: 'Bob',
+        compiled_truth: 'Bob wrote at [example](https://example.com/bob).',
+        timeline: '',
+        frontmatter: {},
+      });
+
+      const batchResult = await scanIntegrity(engine, { limit: 100, batchLoad: true });
+      const seqResult = await scanIntegrity(engine, { limit: 100, batchLoad: false });
+
+      expect(batchResult.bareHits.length).toBe(seqResult.bareHits.length);
+      expect(batchResult.externalHits.length).toBe(seqResult.externalHits.length);
+      expect(batchResult.bareHits.map(h => h.slug).sort()).toEqual(
+        seqResult.bareHits.map(h => h.slug).sort(),
+      );
+      expect(batchResult.externalHits.map(h => h.slug).sort()).toEqual(
+        seqResult.externalHits.map(h => h.slug).sort(),
+      );
+    });
+  });
+
+  describe('validate', () => {
+    test('validate:false (boolean) page is skipped on both paths', async () => {
+      const engine = getEngine();
+
+      await engine.putPage('people/alice', {
+        type: 'person',
+        title: 'Alice',
+        compiled_truth: 'Alice tweeted about something.',
+        timeline: '',
+        frontmatter: {},
+      });
+      await engine.putPage('people/legacy', {
+        type: 'person',
+        title: 'Legacy',
+        compiled_truth: 'Legacy tweeted about old stuff.',
+        timeline: '',
+        frontmatter: { validate: false },
+      });
+
+      const batchResult = await scanIntegrity(engine, { limit: 100, batchLoad: true });
+      const seqResult = await scanIntegrity(engine, { limit: 100, batchLoad: false });
+
+      expect(batchResult.pagesScanned).toBe(seqResult.pagesScanned);
+      expect(batchResult.pagesScanned).toBe(1);
+      expect(batchResult.bareHits.map(h => h.slug)).not.toContain('people/legacy');
+      expect(seqResult.bareHits.map(h => h.slug)).not.toContain('people/legacy');
+    });
+  });
+
+  describe('topPages', () => {
+    test('topPages ordering matches between paths', async () => {
+      const engine = getEngine();
+
+      // Alice has 2 bare-tweet hits; Bob has 1.
+      await engine.putPage('people/alice', {
+        type: 'person',
+        title: 'Alice',
+        compiled_truth: 'Alice tweeted today. Alice tweeted yesterday too.',
+        timeline: '',
+        frontmatter: {},
+      });
+      await engine.putPage('people/bob', {
+        type: 'person',
+        title: 'Bob',
+        compiled_truth: 'Bob tweeted once.',
+        timeline: '',
+        frontmatter: {},
+      });
+
+      const batchResult = await scanIntegrity(engine, { limit: 100, batchLoad: true });
+      const seqResult = await scanIntegrity(engine, { limit: 100, batchLoad: false });
+
+      expect(batchResult.topPages).toEqual(seqResult.topPages);
+    });
+  });
+});
diff --git a/test/skillpack-install.test.ts b/test/skillpack-install.test.ts
index e27316704..753158bf2 100644
--- a/test/skillpack-install.test.ts
+++ b/test/skillpack-install.test.ts
@@ -11,6 +11,7 @@ import {
   mkdtempSync,
   readFileSync,
   rmSync,
+  utimesSync,
   writeFileSync,
 } from 'fs';
 import { dirname, join } from 'path';
@@ -344,6 +345,31 @@ describe('planInstall + applyInstall', () => {
     expect(result.summary.wroteNew).toBeGreaterThan(0);
   });
 
+  it('D-CX-11: --force-unlock works when lock mtime is sub-ms ahead of Date.now (Linux fs jitter)', () => {
+    // Regression guard: on Linux ext4, statSync().mtimeMs has sub-ms precision
+    // while Date.now() is integer ms, so a just-written lock can report a
+    // negative age. If acquireLock does not clamp, stale=false and the
+    // forceUnlock path is unreachable. Simulate deterministically by pushing
+    // the lock's mtime 10ms into the future.
+    const { gbrainRoot } = scratchGbrain();
+    const { workspace, skillsDir } = scratchTarget();
+    const lockFile = join(workspace, '.gbrain-skillpack.lock');
+    writeFileSync(lockFile, '99999');
+    const future = (Date.now() + 10) / 1000;
+    utimesSync(lockFile, future, future);
+    const opts = {
+      gbrainRoot,
+      targetWorkspace: workspace,
+      targetSkillsDir: skillsDir,
+      skillSlug: 'alpha',
+      forceUnlock: true,
+      lockStaleMs: 0,
+    };
+    const plan = planInstall(opts);
+    const result = applyInstall(plan, opts);
+    expect(result.summary.wroteNew).toBeGreaterThan(0);
+  });
+
   it('managed block is written atomically (tmp then rename)', () => {
     const { gbrainRoot } = scratchGbrain();
     const { workspace, skillsDir } = scratchTarget();