fix(facts): seed phase B backfill row_nums past the DB max (#2044 class)

phaseBFenceFacts appended at fence-max+1 with no DB seeding, so on a diverged page (stamped DB rows + missing fence at the resolved path — the same divergence class the writeFactsToFence fix handles) the post-rename UPDATE hit idx_facts_fence_key, the page failed, and the already-renamed fence disagreed with the DB while the row_num-NULL backlog persisted. Seed appended row_nums from MAX(fence max, DB max) per (source_id, slug), mirroring the fence-write fix. Repro test added. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
fix(facts): route exit codes through setCliExitVerdict
2026-08-17 02:12:40 +00:00 · 2026-07-22 11:46:22 -07:00 · 2026-07-22 10:50:45 -07:00 · 2026-07-21 14:45:53 -07:00
22 changed files with 425 additions and 666 deletions
@@ -54,7 +54,7 @@ export function bigintToStringReplacer(_key: string, value: unknown): unknown {
 }

 // CLI-only commands that bypass the operation layer
-export const CLI_ONLY = new Set(['init', 'reinit-pglite', 'upgrade', 'post-upgrade', 'check-update', 'integrations', 'publish', 'check-backlinks', 'lint', 'report', 'import', 'export', 'files', 'embed', 'serve', 'call', 'config', 'doctor', 'migrate', 'eval', 'sync', 'extract', 'extract-conversation-facts', 'enrich', 'features', 'autopilot', 'graph-query', 'jobs', 'agent', 'apply-migrations', 'skillpack-check', 'skillpack', 'resolvers', 'integrity', 'repair-jsonb', 'orphans', 'sources', 'mounts', 'dream', 'check-resolvable', 'routing-eval', 'skillify', 'smoke-test', 'providers', 'storage', 'repos', 'code-def', 'code-refs', 'reindex', 'reindex-code', 'reindex-frontmatter', 'code-callers', 'code-callees', 'reconcile-links', 'frontmatter', 'auth', 'friction', 'claw-test', 'book-mirror', 'takes', 'think', 'salience', 'anomalies', 'calibration', 'transcripts', 'models', 'remote', 'recall', 'forget', 'edges-backfill', 'cache', 'ze-switch', 'founder', 'brainstorm', 'lsd', 'schema', 'capture', 'onboard', 'conversation-parser', 'status', 'connect', 'skillopt', 'quarantine', 'self-upgrade', 'advisor', 'watch', 'reindex-search-vector']);
+export const CLI_ONLY = new Set(['init', 'reinit-pglite', 'upgrade', 'post-upgrade', 'check-update', 'integrations', 'publish', 'check-backlinks', 'lint', 'report', 'import', 'export', 'files', 'embed', 'serve', 'call', 'config', 'doctor', 'migrate', 'eval', 'sync', 'extract', 'extract-conversation-facts', 'enrich', 'features', 'autopilot', 'graph-query', 'jobs', 'agent', 'apply-migrations', 'skillpack-check', 'skillpack', 'resolvers', 'integrity', 'repair-jsonb', 'orphans', 'sources', 'mounts', 'dream', 'check-resolvable', 'routing-eval', 'skillify', 'smoke-test', 'providers', 'storage', 'repos', 'code-def', 'code-refs', 'reindex', 'reindex-code', 'reindex-frontmatter', 'code-callers', 'code-callees', 'reconcile-links', 'frontmatter', 'auth', 'friction', 'claw-test', 'book-mirror', 'takes', 'think', 'salience', 'anomalies', 'calibration', 'transcripts', 'models', 'remote', 'recall', 'forget', 'edges-backfill', 'facts', 'cache', 'ze-switch', 'founder', 'brainstorm', 'lsd', 'schema', 'capture', 'onboard', 'conversation-parser', 'status', 'connect', 'skillopt', 'quarantine', 'self-upgrade', 'advisor', 'watch', 'reindex-search-vector']);
 // CLI-only commands whose handlers print their own --help text. These are
 // excluded from the generic short-circuit so detailed per-command and
 // per-subcommand usage stays reachable.
@@ -991,6 +991,8 @@ const THIN_CLIENT_REFUSED_COMMANDS = new Set([
  // hint pointing at the routable MCP tools; per-subcommand splits are
  // a v0.31.x follow-up TODO.
  'takes', 'sources',
+  // #1867: fence-backfill edits local .md fences + stamps the local DB.
+  'facts',
  // v0.32 thin-client routing audit (Codex round 2 findings #2, #4):
  // - `pages` purge-deleted is admin+localOnly (operations.ts:856-864)
  // - `files` list / file_url MCP ops are localOnly (operations.ts:1769-1879)
@@ -1026,6 +1028,7 @@ const THIN_CLIENT_REFUSE_HINTS: Record<string, string> = {
  migrate: "migrate runs on the host's local engine. Run on the host machine.",
  'apply-migrations': 'schema migrations run on the host. SSH and run there.',
  'repair-jsonb': 'repair-jsonb operates on the local DB only.',
+  facts: 'facts fence-backfill edits local entity-page fences. Run on the host machine.',
  integrity: 'integrity scans local files. Run on the host machine.',
  serve: 'serve starts a server. Run on the host, not the thin client.',
  dream: 'dream runs the autopilot cycle on the host. `gbrain remote ping` queues one. (Native `gbrain dream` thin-client routing planned for v0.31.2.)',
@@ -1855,6 +1858,13 @@ async function handleCliOnly(command: string, args: string[]) {
        await runEdgesBackfill(engine, args);
        break;
      }
+      case 'facts': {
+        // #1867 — re-runnable fence-backfill for row_num-NULL legacy fact
+        // rows (idempotent v0_32_2 phase B, exposed as an operator command).
+        const { runFactsCommand } = await import('./commands/facts.ts');
+        await runFactsCommand(engine, args);
+        break;
+      }
      case 'whoknows': {
        // v0.33 (Issue #?): expertise + relationship-proximity routing.
        // MCP op `find_experts` (read-scoped) backs the same code path; CLI
@@ -2335,6 +2345,7 @@ TOOLS
  check-backlinks <check|fix> [dir]  Find/fix missing back-links across brain
  lint <dir|file> [--fix]            Catch LLM artifacts, placeholder dates, bad frontmatter
  orphans [--json] [--count]         Find pages with no inbound wikilinks
+  facts fence-backfill [--dry-run]   Fence legacy fact rows (row_num NULL) onto entity pages
  salience [--days N] [--kind P]     v0.29: pages ranked by emotional + activity salience
  anomalies [--since D] [--sigma N]  v0.29: cohort-based statistical anomalies (tag, type)
  transcripts recent [--days N]      v0.29: recent raw .txt transcripts (local-only)
@@ -0,0 +1,48 @@
+/**
+ * gbrain facts — fact-store maintenance surface (#1867).
+ *
+ * `fence-backfill` re-runs the v0_32_2 fence-backfill phase on demand.
+ * Remote `extract_facts` deposits that predate the fence-write backstop
+ * (and any legacy DB-only insert) leave `row_num IS NULL` rows that the
+ * cycle extract_facts guard refuses to reconcile past — previously the
+ * only remedy was the one-shot v0_32_2 migration, which the ledger marks
+ * complete and never re-runs. The phase is idempotent (only touches
+ * `row_num IS NULL` rows), so exposing it as a command is safe to re-run
+ * any time the backlog reappears.
+ */
+import type { BrainEngine } from '../core/engine.ts';
+import { setCliExitVerdict } from '../core/cli-force-exit.ts';
+import { phaseBFenceFacts } from './migrations/v0_32_2.ts';
+
+function printHelp(): void {
+  process.stderr.write(
+    `Usage: gbrain facts fence-backfill [--dry-run]\n\n` +
+      `Fence-backfill: appends every legacy fact row (row_num IS NULL) to its\n` +
+      `entity page's \`## Facts\` fence and stamps row_num + source_markdown_slug\n` +
+      `back onto the DB row. Idempotent — re-runs only pick up rows still\n` +
+      `missing a fence assignment. Clears the backlog that makes the cycle's\n` +
+      `extract_facts phase skip fence→DB reconciliation.\n\n` +
+      `  --dry-run   report what would be fenced; no FS or DB writes\n`,
+  );
+}
+
+export async function runFactsCommand(engine: BrainEngine, args: string[]): Promise<void> {
+  const sub = args[0];
+  if (!sub || sub === '--help' || sub === '-h') {
+    printHelp();
+    return;
+  }
+  if (sub !== 'fence-backfill') {
+    process.stderr.write(`Unknown facts subcommand: ${sub}\n`);
+    printHelp();
+    setCliExitVerdict(1);
+    return;
+  }
+
+  const dryRun = args.includes('--dry-run');
+  const result = await phaseBFenceFacts(engine, { dryRun });
+  process.stderr.write(
+    `fence-backfill: ${result.status}${result.detail ? ` — ${result.detail}` : ''}\n`,
+  );
+  if (result.status === 'failed') setCliExitVerdict(1);
+}
@@ -2059,8 +2059,6 @@ export async function registerBuiltinHandlers(
        sourceId,
        windowSeconds,
        brainDir: repoPath,
-        // #2750: worker cancel/timeout/lock-loss propagates into the drain.
-        abortSignal: job.signal,
      });
    } catch (e) {
      if (e instanceof LockUnavailableError) {
@@ -39,6 +39,7 @@ import type { BrainEngine } from '../../core/engine.ts';
 import { loadConfig, toEngineConfig } from '../../core/config.ts';
 import { createEngine } from '../../core/engine-factory.ts';
 import { upsertFactRow, parseFactsFence } from '../../core/facts-fence.ts';
+import { resolvePageFilePath } from '../../core/markdown.ts';

 let testEngineOverride: BrainEngine | null = null;
 export function __setTestEngineOverride(engine: BrainEngine | null): void {
@@ -148,9 +149,16 @@ function isLocalPathDirty(localPath: string): boolean {
  }
 }

-async function phaseBFenceFacts(
+/**
+ * Exported (not just via `__testing`) because `gbrain facts fence-backfill`
+ * (#1867) re-runs this phase on demand: remote `extract_facts` deposits that
+ * predate the fence-write backstop leave row_num-NULL rows the cycle guard
+ * refuses to reconcile past. The phase is idempotent (only touches
+ * `row_num IS NULL` rows), so re-running is always safe.
+ */
+export async function phaseBFenceFacts(
  engine: BrainEngine | null,
-  opts: OrchestratorOpts,
+  opts: Pick<OrchestratorOpts, 'dryRun'>,
 ): Promise<OrchestratorPhaseResult> {
  if (opts.dryRun) {
    // Dry-run: report what WOULD happen without touching FS or DB.
@@ -238,7 +246,11 @@ async function phaseBFenceFacts(
    for (const [key, group] of groups) {
      const [sourceId, entitySlug] = key.split('\0');
      const localPath = localPathById.get(sourceId)!;
-      const filePath = join(localPath, `${entitySlug}.md`);
+      // resolvePageFilePath, NOT a bare join — non-default sources fence
+      // into `<local_path>/.sources/<id>/<slug>.md`, the same path the
+      // fence-write backstop and put_page write-through compute. A bare
+      // join here diverges fence and DB for non-default sources (#2044).
+      const filePath = resolvePageFilePath(localPath, entitySlug, sourceId);
      const tmpPath = `${filePath}.tmp`;

      try {
@@ -269,6 +281,21 @@ async function phaseBFenceFacts(
        const existingFence = parseFactsFence(body);
        const existingKeySet = new Set(existingFence.facts.map(f => `${f.claim}\0${f.source ?? ''}`));

+        // Seed appended row_nums from MAX(fence max, DB max) — same #2044
+        // divergence guard as writeFactsToFence. When the fence at the
+        // resolved path is missing/behind but the DB already holds stamped
+        // rows for this slug (legacy wrong-path fence writes), fence-max+1
+        // collides with idx_facts_fence_key on the post-rename UPDATE,
+        // failing the page and leaving fence and DB disagreeing.
+        const dbMaxRows = await engine.executeRaw<{ max: number | string | null }>(
+          `SELECT MAX(row_num) AS max FROM facts
+            WHERE source_id = $1 AND source_markdown_slug = $2`,
+          [sourceId, entitySlug],
+        );
+        const dbMaxRowNum = Number(dbMaxRows[0]?.max ?? 0) || 0;
+        const fenceMaxRowNum = existingFence.facts.reduce((m, f) => Math.max(m, f.rowNum), 0);
+        let nextRowNum = Math.max(fenceMaxRowNum, dbMaxRowNum) + 1;
+
        const assignments: Array<{ id: string; row_num: number }> = [];
        for (const row of group) {
          const key = `${row.fact}\0${row.source ?? ''}`;
@@ -291,6 +318,7 @@ async function phaseBFenceFacts(
                .toISOString().slice(0, 10)
            : undefined;
          const { body: updated, rowNum } = upsertFactRow(body, {
+            rowNum:     nextRowNum++,
            claim:      row.fact,
            kind:       row.kind,
            confidence: row.confidence,
@@ -381,7 +409,7 @@ async function phaseCVerify(
    for (const g of groups) {
      const localPath = localPathById.get(g.source_id);
      if (!localPath) continue;
-      const filePath = join(localPath, `${g.source_markdown_slug}.md`);
+      const filePath = resolvePageFilePath(localPath, g.source_markdown_slug, g.source_id);
      if (!existsSync(filePath)) {
        mismatches.push(`${g.source_markdown_slug} (file missing)`);
        continue;
@@ -23,10 +23,6 @@
 */

 import type { BrainEngine } from '../engine.ts';
-import { anySignal } from '../abort-check.ts';
-
-/** Fresh cleanup budget for the lock release after the window signal fires. */
-const LOCK_RELEASE_GRACE_MS = 5_000;

 export interface ExtractAtomsDrainDeps {
  /**
@@ -34,13 +30,13 @@ export interface ExtractAtomsDrainDeps {
   * via `withRefreshingLock`. MUST throw when the lock is held by another
   * process (e.g. `LockUnavailableError`) — the drain lets that propagate so
   * the caller can report `cycle_already_running` and exit, matching the
-   * routine cycle's skip contract. The signal bounds lock acquisition too.
+   * routine cycle's skip contract.
   */
-  withLock: <T>(work: () => Promise<T>, signal: AbortSignal) => Promise<T>;
-  /** Process one batch. The signal fires at the drain wallclock deadline. */
-  runBatch: (signal: AbortSignal) => Promise<{ extracted: number; skipped: number }>;
+  withLock: <T>(work: () => Promise<T>) => Promise<T>;
+  /** Process one bounded batch (rediscovers eligibility). Returns counts. */
+  runBatch: () => Promise<{ extracted: number; skipped: number }>;
  /** Count remaining eligible-but-unextracted pages, or null on query error. */
-  countRemaining: (signal: AbortSignal) => Promise<number | null>;
+  countRemaining: () => Promise<number | null>;
  /** Injectable clock. Production: Date.now. */
  now: () => number;
  /** Optional progress sink (one line per batch). */
@@ -52,8 +48,6 @@ export interface ExtractAtomsDrainOpts {
  windowMs: number;
  /** Hard cap on batches (belt-and-suspenders against a 0-progress loop). Default 1000. */
  maxBatches?: number;
-  /** External caller cancellation (worker timeout / shutdown). */
-  abortSignal?: AbortSignal;
 }

 export interface ExtractAtomsDrainResult {
@@ -74,79 +68,35 @@ export async function runExtractAtomsDrain(
  opts: ExtractAtomsDrainOpts,
 ): Promise<ExtractAtomsDrainResult> {
  const maxBatches = opts.maxBatches ?? 1000;
-  const deadline = deps.now() + opts.windowMs;
-  // #2750: the window used to be checked only BETWEEN batches, so one slow
-  // batch (sequential LLM calls) or a hung lock/count/write overran it without
-  // bound (observed window=120s → 282.5s). A real-time deadline signal now
-  // cancels (Postgres) or abandons (PGLite, cooperative) whatever is in
-  // flight; the injected clock still drives loop-boundary checks so the pure
-  // loop stays unit-testable.
-  const signal = anySignal(
-    AbortSignal.timeout(Math.max(1, opts.windowMs)),
-    opts.abortSignal,
-  );
-  const result: ExtractAtomsDrainResult = await deps.withLock(async () => {
+  return deps.withLock(async () => {
+    const deadline = deps.now() + opts.windowMs;
    let extracted = 0;
    let skipped = 0;
    let batches = 0;
    let stopped: ExtractAtomsDrainResult['stopped'] = 'window';

-    while (deps.now() < deadline && !signal.aborted) {
+    while (deps.now() < deadline) {
      if (batches >= maxBatches) { stopped = 'max_batches'; break; }

-      let before: number | null;
-      try {
-        before = await deps.countRemaining(signal);
-      } catch (err) {
-        if (signal.aborted) break;
-        throw err;
-      }
+      const before = await deps.countRemaining();
      if (before === 0) { stopped = 'drained'; break; }

-      // The backlog count consumed the same wallclock budget — re-check so a
-      // slow count can't hand the batch a window that already expired.
-      if (deps.now() >= deadline || signal.aborted) break;
-
-      let r: { extracted: number; skipped: number };
-      try {
-        r = await deps.runBatch(signal);
-      } catch (err) {
-        if (signal.aborted) break;
-        throw err;
-      }
+      const r = await deps.runBatch();
      extracted += r.extracted;
      skipped += r.skipped;
      batches++;
      deps.onBatch?.({ batch: batches, extracted: r.extracted, remaining: before });

-      // A deadline abort inside the batch can surface as zero progress;
-      // window exhaustion wins over the generic no_progress label.
-      if (deps.now() >= deadline || signal.aborted) break;
-
      // Stop if a batch made zero forward progress — extraction is failing or
      // everything left is ineligible (e.g. all skipped). Prevents a hot loop
      // that spends budget without draining.
      if (r.extracted === 0 && r.skipped === 0) { stopped = 'no_progress'; break; }
    }

-    // After the window elapsed, don't spend more unbounded time on a final
-    // count — report remaining as unknown instead of overrunning further.
-    const windowElapsed = signal.aborted || deps.now() >= deadline;
-    let remaining: number | null = null;
-    if (!windowElapsed) {
-      try {
-        remaining = await deps.countRemaining(signal);
-      } catch (err) {
-        if (!signal.aborted) throw err;
-      }
-    }
+    const remaining = await deps.countRemaining();
    if (remaining === 0) stopped = 'drained';
    return { phase: 'extract_atoms', status: 'ok', extracted, skipped, remaining, batches, stopped };
-  }, signal);
-  // Internal window expiry is a normal partial result. An EXTERNAL abort
-  // (worker cancel/timeout/shutdown) must reject so Minion records the abort.
-  if (opts.abortSignal?.aborted) throw opts.abortSignal.reason;
-  return result;
+  });
 }

 // ─── Shared wiring helper (v0.42.x #1685 DECISION 5A) ──────────────────────
@@ -184,8 +134,6 @@ export interface DrainForSourceOpts {
  maxBatches?: number;
  /** Optional per-batch progress sink (stderr line in dream; job progress in the handler). */
  onBatch?: ExtractAtomsDrainDeps['onBatch'];
-  /** Worker cancellation / shutdown signal (Minion `job.signal`). */
-  abortSignal?: AbortSignal;
 }

 export async function runExtractAtomsDrainForSource(
@@ -201,17 +149,12 @@ export async function runExtractAtomsDrainForSource(

  return runExtractAtomsDrain(
    {
-      withLock: (work, signal) => withRefreshingLock(engine, lockId, work, {
-        ttlMinutes: 5,
-        signal,
-        releaseTimeoutMs: LOCK_RELEASE_GRACE_MS,
-      }),
-      runBatch: async (signal) => {
+      withLock: (work) => withRefreshingLock(engine, lockId, work, { ttlMinutes: 5 }),
+      runBatch: async () => {
        const r = await runPhaseExtractAtoms(engine, {
          sourceId: extractionSourceId,
          dryRun: false,
          brainDir: opts.brainDir,
-          abortSignal: signal,
        });
        const d = (r.details ?? {}) as Record<string, unknown>;
        return {
@@ -219,14 +162,10 @@ export async function runExtractAtomsDrainForSource(
          skipped: Number(d.duplicates_skipped ?? 0),
        };
      },
-      countRemaining: (signal) => countExtractAtomsBacklog(engine, extractionSourceId, signal),
+      countRemaining: () => countExtractAtomsBacklog(engine, extractionSourceId),
      now: Date.now,
      onBatch: opts.onBatch,
    },
-    {
-      windowMs: opts.windowSeconds * 1000,
-      maxBatches: opts.maxBatches,
-      abortSignal: opts.abortSignal,
-    },
+    { windowMs: opts.windowSeconds * 1000, maxBatches: opts.maxBatches },
  );
 }
@@ -58,10 +58,6 @@ import { createHash } from 'crypto';
 import { slugifySegment } from '../sync.ts';

 const DEFAULT_BUDGET_USD = 0.3;
-// #2750: fresh wallclock budget for the receipt/rollup bookkeeping writes when
-// the caller's deadline already fired — committed atoms must not lose their
-// cost/receipt trail, but the writes can't be unbounded either.
-const BOOKKEEPING_GRACE_MS = 5_000;

 // v0.42+ TODO: read atom_type enum from active pack manifest at runtime.
 const ATOM_TYPES = [
@@ -159,13 +155,6 @@ export interface ExtractAtomsOpts {
   * `heartbeat()` on the passed reporter.
   */
  progress?: ProgressReporter;
-  /**
-   * #2750: caller deadline/cancellation. Forwarded to every gateway call and
-   * DB query/write so the drain window bounds real lifetime, plus a
-   * cooperative between-item check (the PGLite path, where query abort only
-   * abandons the waiter).
-   */
-  abortSignal?: AbortSignal;
 }

 interface ExtractedAtom {
@@ -223,7 +212,6 @@ export async function discoverExtractablePages(
  engine: BrainEngine,
  sourceId: string,
  affectedSlugs?: string[],
-  abortSignal?: AbortSignal,
 ): Promise<DiscoveredPage[]> {
  const hasFilter = Array.isArray(affectedSlugs) && affectedSlugs.length > 0;
  const sql = `
@@ -263,16 +251,13 @@ export async function discoverExtractablePages(
      slug: string;
      compiled_truth: string;
      content_hash: string;
-    }>(sql, params, { signal: abortSignal });
+    }>(sql, params);
    return rows.map((r) => ({
      slug: r.slug,
      content: r.compiled_truth,
      contentHash: r.content_hash,
    }));
  } catch (err) {
-    // A deadline abort is not a fail-soft condition — propagate so the
-    // caller stops instead of proceeding with an empty page list.
-    if (abortSignal?.aborted) throw err;
    const msg = err instanceof Error ? err.message : String(err);
    console.error(`[extract_atoms] page-discovery query failed: ${msg}`);
    return []; // fail-soft: transcript path still proceeds
@@ -297,7 +282,6 @@ export async function discoverExtractablePages(
 export async function countExtractAtomsBacklog(
  engine: BrainEngine,
  sourceId?: string,
-  abortSignal?: AbortSignal,
 ): Promise<number | null> {
  try {
    // Two modes: scoped (the phase's per-source `remaining`) vs brain-wide
@@ -337,10 +321,9 @@ export async function countExtractAtomsBacklog(
    const params = scoped
      ? [sourceId, extractableTypes, MIN_PAGE_CHARS_FOR_EXTRACTION]
      : [extractableTypes, MIN_PAGE_CHARS_FOR_EXTRACTION];
-    const rows = await engine.executeRaw<{ cnt: string | number }>(sql, params, { signal: abortSignal });
+    const rows = await engine.executeRaw<{ cnt: string | number }>(sql, params);
    return Number(rows[0]?.cnt ?? 0);
  } catch (err) {
-    if (abortSignal?.aborted) throw err;
    const msg = err instanceof Error ? err.message : String(err);
    console.error(`[extract_atoms] backlog count failed: ${msg}`);
    return null;
@@ -367,7 +350,6 @@ export async function atomsExistingForHashes(
  engine: BrainEngine,
  sourceId: string,
  contentHash16s: string[],
-  abortSignal?: AbortSignal,
 ): Promise<Set<string>> {
  if (contentHash16s.length === 0) return new Set();
  try {
@@ -379,11 +361,9 @@ export async function atomsExistingForHashes(
          AND deleted_at IS NULL
          AND frontmatter->>'source_hash' = ANY($2::text[])`,
      [sourceId, contentHash16s],
-      { signal: abortSignal },
    );
    return new Set(rows.map(r => r.h));
  } catch (err) {
-    if (abortSignal?.aborted) throw err;
    const msg = err instanceof Error ? err.message : String(err);
    console.error(`[extract_atoms] batch idempotency check failed (assuming none extracted): ${msg}`);
    return new Set();
@@ -404,7 +384,6 @@ export async function runPhaseExtractAtoms(
 ): Promise<PhaseResult> {
  const sourceId = opts.sourceId ?? 'default';
  const chat = opts._chat ?? gatewayChat;
-  if (opts.abortSignal?.aborted) throw opts.abortSignal.reason;

  // 1a. Get transcripts (test seam OR production discovery).
  //     v0.41.2.1: config loader switched to loadConfigWithEngine() so the
@@ -446,7 +425,7 @@ export async function runPhaseExtractAtoms(
  if (opts._pages !== undefined) {
    pages = opts._pages;
  } else {
-    pages = await discoverExtractablePages(engine, sourceId, opts.affectedSlugs, opts.abortSignal);
+    pages = await discoverExtractablePages(engine, sourceId, opts.affectedSlugs);
  }

  // 2. Apply transcript-side source-hash idempotency in ONE batch query
@@ -458,7 +437,7 @@ export async function runPhaseExtractAtoms(
  // Surface a heartbeat before the batch query so even an instant
  // short-circuit shows a sign of life (closes Issue 2 silent-phase pain).
  opts.progress?.heartbeat(`checking existing atoms for ${allHashes16.length} transcripts`);
-  const existingHashes = await atomsExistingForHashes(engine, sourceId, allHashes16, opts.abortSignal);
+  const existingHashes = await atomsExistingForHashes(engine, sourceId, allHashes16);
  for (const t of transcripts) {
    if (existingHashes.has(t.contentHash.slice(0, 16))) {
      duplicatesSkipped++;
@@ -522,7 +501,6 @@ export async function runPhaseExtractAtoms(
  const failures: Array<{ source: string; error: string }> = [];
  let estimatedSpendUsd = 0;
  const budgetCap = DEFAULT_BUDGET_USD;
-  let deadlineAborted = false;

  // v0.41.19.0 (T3): throttled yield helper. Fires `opts.yieldDuringPhase`
  // every 30s. Cycle.ts threads `buildYieldDuringPhase(lock, outer)` so
@@ -548,12 +526,6 @@ export async function runPhaseExtractAtoms(
  }

  for (const item of work) {
-    // #2750: cooperative between-item abort. Works on every engine — this is
-    // the primary bound on PGLite, where query abort only abandons the waiter.
-    if (opts.abortSignal?.aborted) {
-      deadlineAborted = true;
-      break;
-    }
    await maybeYield();
    if (estimatedSpendUsd >= budgetCap) {
      if (item.kind === 'transcript') transcriptsSkipped++;
@@ -572,22 +544,16 @@ export async function runPhaseExtractAtoms(
          },
        ],
        maxTokens: 2000,
-        abortSignal: opts.abortSignal,
      });
-      // Rough cost estimate — Haiku at ~$0.80/M input + $4/M output.
-      // A completed gateway call is billable even if the deadline fires
-      // immediately afterward, so record usage BEFORE the abort check.
-      estimatedSpendUsd +=
-        (result.usage.input_tokens * 0.8 + result.usage.output_tokens * 4.0) / 1_000_000;
-      if (opts.abortSignal?.aborted) {
-        deadlineAborted = true;
-        break;
-      }
      // Post-await yield: closes the "long LLM call past TTL" hazard
      // codex flagged. The 30s throttle inside maybeYield bounds the
      // actual refresh rate so this is cheap when calls are fast.
      await maybeYield();

+      // Rough cost estimate — Haiku at ~$0.80/M input + $4/M output
+      estimatedSpendUsd +=
+        (result.usage.input_tokens * 0.8 + result.usage.output_tokens * 4.0) / 1_000_000;
+
      const atoms = parseAtomsResponse(result.text);
      if (atoms.length === 0) {
        if (item.kind === 'transcript') transcriptsProcessed++;
@@ -626,7 +592,7 @@ export async function runPhaseExtractAtoms(
              },
              timeline: '',
            },
-            { sourceId, signal: opts.abortSignal },
+            { sourceId },
          );
          totalAtomsExtracted++;
        }
@@ -639,11 +605,6 @@ export async function runPhaseExtractAtoms(
      // Reporter rate-limits to ~1 line/sec; safe to tick every iter.
      opts.progress?.tick(1, `${totalAtomsExtracted} atoms / ${duplicatesSkipped} skipped`);
    } catch (err) {
-      // A deadline abort is a partial result, not a per-item failure.
-      if (opts.abortSignal?.aborted) {
-        deadlineAborted = true;
-        break;
-      }
      failures.push({
        source: originLabel,
        error: err instanceof Error ? err.message : String(err),
@@ -654,12 +615,6 @@ export async function runPhaseExtractAtoms(
  // v0.42 Wave B2: write extract receipt + rollup row when the phase
  // actually extracted atoms. Both are best-effort per F-OUT-19 —
  // audit-trail / search-visibility surfaces don't block the phase result.
-  //
-  // #2750: bookkeeping runs on a FRESH short grace signal, never the caller's
-  // work deadline — the deadline may have already fired (partial run) and
-  // committed atoms must not lose their receipt/cost trail; but the writes
-  // stay bounded so the overrun is capped at the grace window.
-  const bookkeepingSignal = opts.dryRun ? undefined : AbortSignal.timeout(BOOKKEEPING_GRACE_MS);
  if (!opts.dryRun && totalAtomsExtracted > 0) {
    const runId = `atoms-${Date.now().toString(36)}-${sourceId.slice(0, 4)}`;
    try {
@@ -674,24 +629,19 @@ export async function runPhaseExtractAtoms(
        summary:
          `Extracted ${totalAtomsExtracted} atoms from ` +
          `${transcriptsProcessed} transcripts + ${pagesProcessed} pages.`,
-      }, { signal: bookkeepingSignal });
+      });
    } catch (err) {
      console.error(`[extract_atoms] receipt write failed: ${(err as Error).message}`);
    }
  }
  if (!opts.dryRun) {
-    try {
-      await upsertExtractRollup(engine, {
-        kind: 'atoms',
-        source_id: sourceId,
-        cost_delta: estimatedSpendUsd,
-        // A deadline-truncated run is not a completed round.
-        round_completed_delta: failures.length === 0 && !deadlineAborted ? 1 : 0,
-        halt_delta: failures.length > 0 ? 1 : 0,
-      }, { signal: bookkeepingSignal });
-    } catch (err) {
-      console.error(`[extract_atoms] rollup write failed: ${(err as Error).message}`);
-    }
+    await upsertExtractRollup(engine, {
+      kind: 'atoms',
+      source_id: sourceId,
+      cost_delta: estimatedSpendUsd,
+      round_completed_delta: failures.length === 0 ? 1 : 0,
+      halt_delta: failures.length > 0 ? 1 : 0,
+    });
  }

  return {
@@ -720,7 +670,6 @@ export async function runPhaseExtractAtoms(
      budget_usd: budgetCap,
      source_id: sourceId,
      dry_run: opts.dryRun ?? false,
-      deadline_aborted: deadlineAborted,
    },
  };
 }
@@ -176,9 +176,11 @@ export async function runExtractFacts(
  if (legacyCount > 0) {
    result.guardTriggered = true;
    result.warnings.push(
-      `extract_facts: ${legacyCount} legacy v0.31 fact rows pending fence backfill. ` +
-      `Run \`gbrain apply-migrations --yes\` to complete v0_32_2 before this phase ` +
-      `can safely reconcile fence → DB.`,
+      `extract_facts: ${legacyCount} legacy fact rows pending fence backfill ` +
+      `(row_num IS NULL — v0.31 rows or remote extract_facts deposits that ` +
+      `predate the fence backstop). Run \`gbrain facts fence-backfill\` ` +
+      `(idempotent, re-runnable) before this phase can safely reconcile ` +
+      `fence → DB.`,
    );
    return result;
  }
@@ -26,8 +26,7 @@ import type { BrainEngine } from './engine.ts';

 export interface DbLockHandle {
  id: string;
-  /** Optional signal bounds the release DELETE (deadline-bound callers). */
-  release: (signal?: AbortSignal) => Promise<void>;
+  release: () => Promise<void>;
  refresh: () => Promise<void>;
 }

@@ -174,7 +173,6 @@ export async function tryAcquireDbLock(
  engine: BrainEngine,
  lockId: string,
  ttlMinutes: number = DEFAULT_TTL_MINUTES,
-  opts: { signal?: AbortSignal } = {},
 ): Promise<DbLockHandle | null> {
  const pid = process.pid;
  const host = hostname();
@@ -207,26 +205,20 @@ export async function tryAcquireDbLock(
    // `gbrain sync --break-lock --max-age <s>` uses last_refreshed_at (not
    // acquired_at) to identify wedged-but-alive holders without stealing
    // healthy long-running holders that are actively refreshing.
-    // #2750: routed through executeRaw so a deadline-bound caller's signal
-    // can cancel a hung acquire (pool exhaustion). Cancellation is
-    // transactional; in the rare ambiguous-commit case the row's TTL is the
-    // backstop (drain locks use a short 5-minute TTL).
-    const rows = await engine.executeRaw<{ id: string }>(
-      `INSERT INTO gbrain_cycle_locks (id, holder_pid, holder_host, acquired_at, ttl_expires_at, last_refreshed_at)
-       VALUES ($1, $2, $3, NOW(), NOW() + $4::interval, NOW())
-       ON CONFLICT (id) DO UPDATE
-         SET holder_pid = $2,
-             holder_host = $3,
-             acquired_at = NOW(),
-             ttl_expires_at = NOW() + $4::interval,
-             last_refreshed_at = NOW()
-         WHERE gbrain_cycle_locks.ttl_expires_at < NOW()
-           AND (gbrain_cycle_locks.last_refreshed_at IS NULL
-                OR gbrain_cycle_locks.last_refreshed_at < NOW() - $5 * INTERVAL '1 second')
-       RETURNING id`,
-      [lockId, pid, host, ttl, stealGraceSeconds],
-      { signal: opts.signal },
-    );
+    const rows: Array<{ id: string }> = await sql`
+      INSERT INTO gbrain_cycle_locks (id, holder_pid, holder_host, acquired_at, ttl_expires_at, last_refreshed_at)
+      VALUES (${lockId}, ${pid}, ${host}, NOW(), NOW() + ${ttl}::interval, NOW())
+      ON CONFLICT (id) DO UPDATE
+        SET holder_pid = ${pid},
+            holder_host = ${host},
+            acquired_at = NOW(),
+            ttl_expires_at = NOW() + ${ttl}::interval,
+            last_refreshed_at = NOW()
+        WHERE gbrain_cycle_locks.ttl_expires_at < NOW()
+          AND (gbrain_cycle_locks.last_refreshed_at IS NULL
+               OR gbrain_cycle_locks.last_refreshed_at < NOW() - ${stealGraceSeconds} * INTERVAL '1 second')
+      RETURNING id
+    `;
    if (rows.length === 0) return null;
    const deregister = registerCleanup(`db-lock:${lockId}`, async () => {
      await sql`
@@ -249,17 +241,12 @@ export async function tryAcquireDbLock(
          [ttl, lockId, pid],
        );
      },
-      release: async (signal?: AbortSignal) => {
+      release: async () => {
        deregister();
-        // Direct session pool (same rationale as refresh, #1794) + optional
-        // signal so a deadline-bound caller's release can't hang forever on
-        // an exhausted pooler. TTL is the backstop if the DELETE is cancelled.
-        await engine.executeRawDirect(
-          `DELETE FROM gbrain_cycle_locks
-            WHERE id = $1 AND holder_pid = $2`,
-          [lockId, pid],
-          { signal },
-        );
+        await sql`
+          DELETE FROM gbrain_cycle_locks
+          WHERE id = ${lockId} AND holder_pid = ${pid}
+        `;
      },
    };
  }
@@ -316,11 +303,6 @@ export async function tryAcquireDbLock(
  const first = await acquireOnce();
  if (first) return first;

-  // #2750: deadline-bound callers prefer an honest busy result over the
-  // best-effort same-host takeover below, whose inspect/delete/retry calls
-  // are not signal-bounded. The initial upsert already reclaims expired locks.
-  if (opts.signal) return null;
-
  // v0.42 (#1780 Gap 3): the lock is held and its TTL hasn't expired (the
  // upsert's ON CONFLICT ... WHERE ttl_expires_at < NOW() returned no row).
  // If the holder is on THIS host, provably dead, and past the grace window,
@@ -814,10 +796,6 @@ export interface WithRefreshingLockOpts {
  ttlMinutes?: number;
  /** Heartbeat-fail threshold in ms — abort if SELECT 1 takes longer. Default 30000. */
  heartbeatTimeoutMs?: number;
-  /** #2750: bound lock acquisition with the caller's deadline signal. */
-  signal?: AbortSignal;
-  /** Fresh cleanup budget for the release DELETE when `signal` is set. Default 5000. */
-  releaseTimeoutMs?: number;
 }

 /**
@@ -837,7 +815,7 @@ export async function withRefreshingLock<T>(
  // Refresh 6x per TTL window so a missed tick doesn't expire the lock.
  const refreshIntervalMs = Math.max(15000, (ttlMinutes * 60 * 1000) / 6);

-  const handle = await tryAcquireDbLock(engine, lockId, ttlMinutes, { signal: opts.signal });
+  const handle = await tryAcquireDbLock(engine, lockId, ttlMinutes);
  if (!handle) throw new LockUnavailableError(lockId);

  let healthOk = true;
@@ -876,13 +854,7 @@ export async function withRefreshingLock<T>(
    return await work();
  } finally {
    clearInterval(interval);
-    // #2750: when the caller is deadline-bound, its work signal may already
-    // have fired — release on a FRESH short grace signal so cleanup neither
-    // inherits the spent deadline nor hangs unbounded. TTL is the backstop.
-    const releaseSignal = opts.signal
-      ? AbortSignal.timeout(opts.releaseTimeoutMs ?? 5_000)
-      : undefined;
-    try { await handle.release(releaseSignal); } catch { /* idempotent; TTL backstop */ }
+    try { await handle.release(); } catch { /* idempotent */ }
    if (!healthOk) {
      // Surface that the heartbeat detected backend trouble — caller can
      // log to the connection-events audit if desired.
@@ -696,16 +696,8 @@ export interface BrainEngine {
   * is included in the INSERT column list so ON CONFLICT (source_id, slug)
   * DO UPDATE actually targets the intended row instead of fabricating a
   * duplicate at (default, slug). Multi-source brains MUST pass sourceId.
-   *
-   * `opts.signal` (#2750): optional cancellation for deadline-bound writers.
-   * Postgres cancels the in-flight statement; PGLite pre-checks only (query
-   * cancellation is not possible in-process — cooperative abort between calls).
   */
-  putPage(
-    slug: string,
-    page: PageInput,
-    opts?: { sourceId?: string; signal?: AbortSignal },
-  ): Promise<Page>;
+  putPage(slug: string, page: PageInput, opts?: { sourceId?: string }): Promise<Page>;
  /**
   * v0.41.13 (#1309) — identity-based dedup pre-check for the import pipeline.
   *
@@ -1747,13 +1739,14 @@ export interface BrainEngine {
   * single-row supersede flow because fence reconciliation is the canonical
   * source-of-truth direction, not the consolidator path.
   *
-   * Insertion is atomic per call: all rows commit in a single transaction
-   * or none commit (the transaction rolls back on any constraint
-   * violation, e.g. the v51 partial UNIQUE index on
-   * `(source_id, source_markdown_slug, row_num)`).
+   * Insertion runs in a single transaction. A collision on the v51
+   * partial UNIQUE index `(source_id, source_markdown_slug, row_num)`
+   * skips ONLY that row (ON CONFLICT DO NOTHING, #2044) — the rest of
+   * the batch still commits, so a redundant deposit against an
+   * already-indexed fence row is idempotent instead of a hard failure.
   *
-   * Returns the inserted ids in input-order so callers can correlate
-   * fence-row → DB-id without a separate lookup.
+   * Returns the inserted ids in input-order (colliding rows omitted) so
+   * callers can correlate fence-row → DB-id without a separate lookup.
   */
  insertFacts(
    rows: Array<NewFact & { row_num: number; source_markdown_slug: string }>,
@@ -187,7 +187,6 @@ function buildReceiptFrontmatter(input: ExtractReceiptInput): Record<string, unk
 export async function writeReceipt(
  engine: BrainEngine,
  input: ExtractReceiptInput,
-  opts?: { signal?: AbortSignal },
 ): Promise<{ slug: string; page: Page }> {
  const slug = receiptSlug(input);
  const title = `${input.kind} — ${input.round} — ${input.source_id}`;
@@ -202,7 +201,7 @@ export async function writeReceipt(
      compiled_truth,
      frontmatter,
    },
-    { sourceId: input.source_id, signal: opts?.signal },
+    { sourceId: input.source_id },
  );

  return { slug, page };
@@ -70,7 +70,6 @@ function today(): string {
 export async function upsertExtractRollup(
  engine: BrainEngine,
  input: RollupUpsertInput,
-  opts?: { signal?: AbortSignal },
 ): Promise<{ ok: boolean; error?: string }> {
  const day = input.day ?? today();
  const cost = input.cost_delta ?? 0;
@@ -97,12 +96,9 @@ export async function upsertExtractRollup(
         rollup_write_failures  = extract_rollup_7d.rollup_write_failures  + EXCLUDED.rollup_write_failures,
         updated_at             = now()`,
      [input.kind, input.source_id, day, cost, halts, evalFails, evalPasses, completed, failures],
-      { signal: opts?.signal },
    );
    return { ok: true };
  } catch (err) {
-    // Signal-bounded callers get the abort surfaced, not a swallowed `ok:false`.
-    if (opts?.signal?.aborted) throw err;
    const msg = (err as Error).message || String(err);
    // Don't spam: log once per process per (kind, day) error class.
    rollupErrorLogOnce(input.kind, day, msg);
@@ -218,11 +218,27 @@ export async function writeFactsToFence(
      }

      // 2. Upsert each fact onto the fence in input order. row_num
-      //    monotonically increases (max-existing + 1 per call, append-only).
+      //    monotonically increases, append-only, seeded from the MAX of
+      //    the fence and the DB index (#2044): when fence and DB have
+      //    diverged (e.g. legacy writes that stamped DB rows against a
+      //    fence at a path this code no longer reads), fence-max+1 can
+      //    collide with an existing DB row_num, tripping
+      //    idx_facts_fence_key and rolling back the whole batch.
+      const dbMaxRows = await engine.executeRaw<{ max: number | string | null }>(
+        `SELECT MAX(row_num) AS max FROM facts
+          WHERE source_id = $1 AND source_markdown_slug = $2`,
+        [target.sourceId, target.slug],
+      );
+      const dbMaxRowNum = Number(dbMaxRows[0]?.max ?? 0) || 0;
+      const fenceMaxRowNum = parseFactsFence(body).facts
+        .reduce((m, f) => Math.max(m, f.rowNum), 0);
+      let nextRowNum = Math.max(fenceMaxRowNum, dbMaxRowNum) + 1;
+
      const assignedRowNums: number[] = [];
      for (const f of facts) {
        const validFromStr = (f.validFrom ?? new Date()).toISOString().slice(0, 10);
        const { body: updated, rowNum } = upsertFactRow(body, {
+          rowNum:      nextRowNum++,
          claim:       f.fact,
          kind:        (f.kind ?? 'fact') as 'fact' | 'event' | 'preference' | 'commitment' | 'belief',
          confidence:  f.confidence ?? 1.0,
@@ -1003,15 +1003,7 @@ export class PGLiteEngine implements BrainEngine {
    return { slug: r.slug, id: Number(r.id) };
  }

-  async putPage(
-    slug: string,
-    page: PageInput,
-    opts?: { sourceId?: string; signal?: AbortSignal },
-  ): Promise<Page> {
-    // #2750: PGLite is in-process WASM — no query cancellation. Pre-check so
-    // an already-fired deadline skips the write; abort is cooperative
-    // between calls (same posture as executeRaw's documented gap).
-    if (opts?.signal?.aborted) throw new DOMException('aborted', 'AbortError');
+  async putPage(slug: string, page: PageInput, opts?: { sourceId?: string }): Promise<Page> {
    slug = validateSlug(slug);
    const hash = page.content_hash || contentHash(page);
    const frontmatter = page.frontmatter || {};
@@ -4110,11 +4102,13 @@ export class PGLiteEngine implements BrainEngine {
  ): Promise<{ inserted: number; ids: number[] }> {
    if (rows.length === 0) return { inserted: 0, ids: [] };

-    // Single transaction so the v51 partial UNIQUE index can roll back the
-    // whole batch on constraint violation. Per-row INSERTs (not multi-row
-    // VALUES) keep the embedding-vs-no-embedding branching readable; batch
-    // sizes are small (5-30 rows per page in practice) so the loop overhead
-    // is negligible vs the embedding compute cost.
+    // Single transaction; per-row INSERTs (not multi-row VALUES) keep the
+    // embedding-vs-no-embedding branching readable; batch sizes are small
+    // (5-30 rows per page in practice) so the loop overhead is negligible
+    // vs the embedding compute cost. #2044: ON CONFLICT DO NOTHING on the
+    // v51 partial UNIQUE index makes a residual fence/DB row_num collision
+    // skip that row instead of rolling back the whole batch (parity with
+    // postgres-engine.ts).
    const ids = await this.db.transaction(async (tx) => {
      const out: number[] = [];
      for (const input of rows) {
@@ -4157,7 +4151,11 @@ export class PGLiteEngine implements BrainEngine {
                 $14, $15,
                 $16, $17, $18, $19,
                 $20
-               ) RETURNING id`
+               )
+               ON CONFLICT (source_id, source_markdown_slug, row_num)
+                 WHERE row_num IS NOT NULL
+                 DO NOTHING
+               RETURNING id`
            : `INSERT INTO facts (
                 source_id, entity_slug, fact, kind, visibility, notability, context,
                 valid_from, valid_until, source, source_session, confidence,
@@ -4171,12 +4169,16 @@ export class PGLiteEngine implements BrainEngine {
                 $15, $16,
                 $17, $18, $19, $20,
                 $21
-               ) RETURNING id`,
+               )
+               ON CONFLICT (source_id, source_markdown_slug, row_num)
+                 WHERE row_num IS NOT NULL
+                 DO NOTHING
+               RETURNING id`,
          embedStr === null
            ? [ctx.source_id, entitySlug, input.fact, kind, visibility, notability, context, validFrom, validUntil, input.source, sourceSession, confidence, embeddedAt, input.row_num, input.source_markdown_slug, claimMetric, claimValue, claimUnit, claimPeriod, eventType]
            : [ctx.source_id, entitySlug, input.fact, kind, visibility, notability, context, validFrom, validUntil, input.source, sourceSession, confidence, embedStr, embeddedAt, input.row_num, input.source_markdown_slug, claimMetric, claimValue, claimUnit, claimPeriod, eventType],
        );
-        out.push(ins.rows[0].id);
+        if (ins.rows[0]) out.push(ins.rows[0].id);
      }
      return out;
    });
@@ -72,32 +72,6 @@ function escapeSqlStringLiteral(value: string): string {
  return value.replace(/'/g, "''");
 }

-/**
- * #2750: race a promise against an AbortSignal, detaching the listener once
- * settled (long-lived drain signals are reused across many calls, so a bare
- * Promise.race would leak one listener per call). The abandoned promise keeps
- * running; used only for pool-acquisition waits where that is harmless.
- */
-function waitForSignal<T>(work: Promise<T>, signal?: AbortSignal): Promise<T> {
-  if (!signal) return work;
-  if (signal.aborted) return Promise.reject(new DOMException('aborted', 'AbortError'));
-  return new Promise<T>((resolve, reject) => {
-    let settled = false;
-    const finish = (fn: () => void) => {
-      if (settled) return;
-      settled = true;
-      signal.removeEventListener('abort', onAbort);
-      fn();
-    };
-    const onAbort = () => finish(() => reject(new DOMException('aborted', 'AbortError')));
-    signal.addEventListener('abort', onAbort, { once: true });
-    work.then(
-      (value) => finish(() => resolve(value)),
-      (err) => finish(() => reject(err)),
-    );
-  });
-}
-
 export function getPostgresSchema(
  dims: number = DEFAULT_EMBEDDING_DIMENSIONS,
  model: string = DEFAULT_EMBEDDING_MODEL,
@@ -1087,12 +1061,7 @@ export class PostgresEngine implements BrainEngine {
    });
  }

-  async putPage(
-    slug: string,
-    page: PageInput,
-    opts?: { sourceId?: string; signal?: AbortSignal },
-  ): Promise<Page> {
-    if (opts?.signal?.aborted) throw new DOMException('aborted', 'AbortError');
+  async putPage(slug: string, page: PageInput, opts?: { sourceId?: string }): Promise<Page> {
    slug = validateSlug(slug);
    const sql = this.sql;
    const hash = page.content_hash || contentHash(page);
@@ -1127,7 +1096,7 @@ export class PostgresEngine implements BrainEngine {
    const sourceUri = page.source_uri ?? null;
    const ingestedVia = page.ingested_via ?? null;
    const ingestedAt = (sourceKind || sourceUri || ingestedVia) ? new Date() : null;
-    const pending = sql`
+    const rows = await sql`
      INSERT INTO pages (source_id, slug, type, page_kind, title, compiled_truth, timeline, frontmatter, content_hash, updated_at, effective_date, effective_date_source, import_filename, chunker_version, source_path, source_kind, source_uri, ingested_via, ingested_at)
      VALUES (${sourceId}, ${slug}, ${page.type}, ${pageKind}, ${page.title}, ${page.compiled_truth}, ${page.timeline || ''}, ${sql.json(frontmatter as Parameters<typeof sql.json>[0])}, ${hash}, now(), ${effectiveDate}, ${effectiveDateSource}, ${importFilename}, COALESCE(${chunkerVersion}::smallint, ${MARKDOWN_CHUNKER_VERSION}), ${sourcePath}, ${sourceKind}, ${sourceUri}, ${ingestedVia}, ${ingestedAt})
      ON CONFLICT (source_id, slug) DO UPDATE SET
@@ -1150,22 +1119,6 @@ export class PostgresEngine implements BrainEngine {
        ingested_at           = COALESCE(EXCLUDED.ingested_at,           pages.ingested_at)
      RETURNING id, source_id, slug, type, title, compiled_truth, timeline, frontmatter, content_hash, created_at, updated_at, effective_date, effective_date_source, import_filename, source_kind, source_uri, ingested_via, ingested_at
    `;
-    // #2750: cancel the in-flight statement when the caller's deadline fires,
-    // same .cancel() wiring as runUnsafe (postgres.js pending queries).
-    if (opts?.signal) {
-      const signal = opts.signal;
-      const onAbort = () => {
-        try { (pending as unknown as { cancel?: () => void }).cancel?.(); } catch { /* best-effort */ }
-      };
-      signal.addEventListener('abort', onAbort, { once: true });
-      try {
-        const rows = await pending;
-        return rowToPage(rows[0]);
-      } finally {
-        signal.removeEventListener('abort', onAbort);
-      }
-    }
-    const rows = await pending;
    return rowToPage(rows[0]);
  }

@@ -4349,10 +4302,12 @@ export class PostgresEngine implements BrainEngine {
    // ONCE per process so the cast matches the actual column type
    // (halfvec vs vector). The probe is cached after first call.
    const castSuffix = await this.resolveFactsEmbeddingCast();
-    // Single transaction so the v51 partial UNIQUE index can roll back
-    // the whole batch on constraint violation. Per-row INSERTs (not
-    // multi-row VALUES) keep the embedding-vs-no-embedding branching
-    // readable; batch sizes are small (5-30 rows per page in practice).
+    // Single transaction; per-row INSERTs (not multi-row VALUES) keep the
+    // embedding-vs-no-embedding branching readable; batch sizes are small
+    // (5-30 rows per page in practice). #2044: ON CONFLICT DO NOTHING on
+    // the v51 partial UNIQUE index makes a residual fence/DB row_num
+    // collision skip that row instead of rolling back the whole batch —
+    // the fence stays system-of-record and reconciliation catches up.
    // No supersede flow in this path — fence reconciliation is the
    // canonical source-of-truth direction, not the consolidator path.
    const ids = await sql.begin(async (tx) => {
@@ -4393,9 +4348,13 @@ export class PostgresEngine implements BrainEngine {
            ${input.row_num}, ${input.source_markdown_slug},
            ${claimMetric}, ${claimValue}, ${claimUnit}, ${claimPeriod},
            ${eventType}
-          ) RETURNING id
+          )
+          ON CONFLICT (source_id, source_markdown_slug, row_num)
+            WHERE row_num IS NOT NULL
+            DO NOTHING
+          RETURNING id
        `;
-        out.push(Number(ins[0].id));
+        if (ins[0]) out.push(Number(ins[0].id));
      }
      return out;
    });
@@ -5854,16 +5813,11 @@ export class PostgresEngine implements BrainEngine {
    params?: unknown[],
    opts?: { signal?: AbortSignal },
  ): Promise<T[]> {
-    // #2750: an already-fired signal short-circuits BEFORE any pool routing,
-    // and the direct-pool acquisition itself is signal-bounded — under pooler
-    // exhaustion `ddl()` can stall indefinitely, which used to make even a
-    // "bounded" lock release hang past its caller's deadline.
-    if (opts?.signal?.aborted) throw new DOMException('aborted', 'AbortError');
    // Inside an open transaction, _sql is the reserved tx connection (set via
    // defineProperty in transaction()); never reroute off it.
    const inTransaction = this._sql !== null && this.connectionManager?.peekReadPool() !== this._sql;
    const conn = (!inTransaction && this.connectionManager?.isDualPoolActive())
-      ? await waitForSignal(this.connectionManager.ddl(), opts?.signal)
+      ? await this.connectionManager.ddl()
      : this.sql;
    return this.runUnsafe<T>(conn, sql, params, opts);
  }
@@ -17,7 +17,6 @@ import { runPhaseExtractAtoms, parseAtomsResponse } from '../../src/core/cycle/e
 import { runPhaseSynthesizeConcepts } from '../../src/core/cycle/synthesize-concepts.ts';
 import { resetPgliteState } from '../helpers/reset-pglite.ts';
 import type { ChatResult, ChatOpts } from '../../src/core/ai/gateway.ts';
-import type { BrainEngine } from '../../src/core/engine.ts';

 let engine: PGLiteEngine;

@@ -178,180 +177,6 @@ describe('v0.41 T5: runPhaseExtractAtoms via stubbed chat', () => {
    expect((result.details?.failures as unknown[]).length).toBe(1);
  });

-  // ── #2750: caller deadline bounds the phase ────────────────────────────
-
-  test('caller deadline aborts a hung chat before processing the next item', async () => {
-    let calls = 0;
-    const chat = async (opts: ChatOpts) => {
-      calls++;
-      return await new Promise<never>((_resolve, reject) => {
-        const signal = opts.abortSignal;
-        if (!signal) return reject(new Error('missing abort signal'));
-        if (signal.aborted) return reject(signal.reason);
-        signal.addEventListener('abort', () => reject(signal.reason), { once: true });
-      });
-    };
-    const started = Date.now();
-    const result = await runPhaseExtractAtoms(engine, {
-      _transcripts: [
-        { filePath: '/hung.txt', content: 'a', contentHash: 'hung-a' },
-        { filePath: '/never.txt', content: 'b', contentHash: 'hung-b' },
-      ],
-      _pages: [],
-      _chat: chat as typeof import('../../src/core/ai/gateway.ts').chat,
-      abortSignal: AbortSignal.timeout(25),
-    });
-    expect(Date.now() - started).toBeLessThan(2_000);
-    expect(calls).toBe(1);
-    expect(result.status).toBe('ok');
-    expect(result.details?.deadline_aborted).toBe(true);
-    expect(result.details?.atoms_extracted).toBe(0);
-    expect(result.details?.failures).toEqual([]);
-  });
-
-  test('billable chat usage is counted when the deadline fires as the response resolves', async () => {
-    const controller = new AbortController();
-    const chat = async (opts: ChatOpts): Promise<ChatResult> => {
-      controller.abort(new DOMException('deadline', 'TimeoutError'));
-      return stubChat(`[{"title":"late","atom_type":"insight","body":"b"}]`, {
-        input_tokens: 1_000,
-        output_tokens: 500,
-      })(opts);
-    };
-    const result = await runPhaseExtractAtoms(engine, {
-      _transcripts: [{ filePath: '/late.txt', content: 'a', contentHash: 'late' }],
-      _pages: [],
-      _chat: chat,
-      abortSignal: controller.signal,
-    });
-    expect(result.details?.deadline_aborted).toBe(true);
-    expect(Number(result.details?.estimated_spend_usd)).toBeGreaterThan(0);
-    expect(result.details?.atoms_extracted).toBe(0);
-  });
-
-  test('deadline after partial progress still writes receipt and incomplete rollup', async () => {
-    const controller = new AbortController();
-    let calls = 0;
-    let notifySecondChat!: () => void;
-    const secondChatStarted = new Promise<void>((resolve) => { notifySecondChat = resolve; });
-    const chat = async (opts: ChatOpts): Promise<ChatResult> => {
-      calls++;
-      if (calls === 1) {
-        return stubChat(`[{"title":"committed","atom_type":"insight","body":"b"}]`)(opts);
-      }
-      notifySecondChat();
-      return await new Promise<never>((_resolve, reject) => {
-        const signal = opts.abortSignal;
-        if (!signal) return reject(new Error('missing abort signal'));
-        signal.addEventListener('abort', () => reject(signal.reason), { once: true });
-      });
-    };
-
-    const pending = runPhaseExtractAtoms(engine, {
-      _transcripts: [
-        { filePath: '/committed.txt', content: 'a', contentHash: 'committed-a' },
-        { filePath: '/hung.txt', content: 'b', contentHash: 'hung-b' },
-      ],
-      _pages: [],
-      _chat: chat,
-      abortSignal: controller.signal,
-    });
-    await secondChatStarted;
-    controller.abort(new DOMException('deadline', 'TimeoutError'));
-    const result = await pending;
-
-    const atoms = await engine.executeRaw<{ n: number }>(
-      `SELECT COUNT(*)::int AS n FROM pages WHERE type = 'atom'`,
-    );
-    const receipts = await engine.executeRaw<{ n: number }>(
-      `SELECT COUNT(*)::int AS n FROM pages WHERE type = 'extract_receipt'`,
-    );
-    const rollups = await engine.executeRaw<{
-      cost_usd: string | number;
-      round_completed_count: string | number;
-    }>(
-      `SELECT cost_usd, round_completed_count
-         FROM extract_rollup_7d
-        WHERE kind = 'atoms' AND source_id = 'default'`,
-    );
-    expect(result.details?.deadline_aborted).toBe(true);
-    expect(atoms[0].n).toBe(1);
-    expect(receipts[0].n).toBe(1);
-    expect(Number(rollups[0].cost_usd)).toBeGreaterThan(0);
-    expect(Number(rollups[0].round_completed_count)).toBe(0);
-  });
-
-  test('bookkeeping runs on a fresh grace signal, not the fired work deadline', async () => {
-    const controller = new AbortController();
-    let putCalls = 0;
-    let receiptSignal: AbortSignal | undefined;
-    let rollupSignal: AbortSignal | undefined;
-    const signalAwareEngine = {
-      executeRaw: async (sql: string, _params?: unknown[], opts?: { signal?: AbortSignal }) => {
-        if (sql.includes('INSERT INTO extract_rollup_7d')) rollupSignal = opts?.signal;
-        return [];
-      },
-      putPage: async (_slug: string, _page: unknown, opts?: { signal?: AbortSignal }) => {
-        putCalls++;
-        if (putCalls === 1) {
-          // Atom write in flight; the work deadline fires before bookkeeping.
-          controller.abort(new DOMException('work deadline', 'TimeoutError'));
-        } else {
-          receiptSignal = opts?.signal;
-        }
-        return {};
-      },
-    } as unknown as BrainEngine;
-
-    const result = await runPhaseExtractAtoms(signalAwareEngine, {
-      _transcripts: [{ filePath: '/one.txt', content: 'a', contentHash: 'one' }],
-      _pages: [],
-      _chat: stubChat(`[{"title":"one","atom_type":"insight","body":"b"}]`),
-      abortSignal: controller.signal,
-    });
-
-    expect(result.details?.atoms_extracted).toBe(1);
-    expect(putCalls).toBe(2); // atom write + receipt write
-    expect(receiptSignal).toBeDefined();
-    expect(receiptSignal).not.toBe(controller.signal);
-    expect(receiptSignal?.aborted).toBe(false);
-    expect(rollupSignal).toBe(receiptSignal);
-  });
-
-  test('caller deadline cancels a hung atom write and stops the phase', async () => {
-    const controller = new AbortController();
-    let notifyWriteStarted!: () => void;
-    const writeStarted = new Promise<void>((resolve) => { notifyWriteStarted = resolve; });
-    let writeCalls = 0;
-    const signalAwareEngine = {
-      executeRaw: async () => [],
-      putPage: async (_slug: string, _page: unknown, opts?: { signal?: AbortSignal }) => {
-        writeCalls++;
-        notifyWriteStarted();
-        return await new Promise<never>((_resolve, reject) => {
-          const signal = opts?.signal;
-          if (!signal) return reject(new Error('missing abort signal'));
-          if (signal.aborted) return reject(signal.reason);
-          signal.addEventListener('abort', () => reject(signal.reason), { once: true });
-        });
-      },
-    } as unknown as BrainEngine;
-
-    const pending = runPhaseExtractAtoms(signalAwareEngine, {
-      _transcripts: [{ filePath: '/hung-write.txt', content: 'a', contentHash: 'hung-write' }],
-      _pages: [],
-      _chat: stubChat(`[{"title":"hung write","atom_type":"insight","body":"b"}]`),
-      abortSignal: controller.signal,
-    });
-    await writeStarted;
-    controller.abort(new DOMException('deadline', 'TimeoutError'));
-    const result = await pending;
-
-    expect(writeCalls).toBe(1);
-    expect(result.details?.deadline_aborted).toBe(true);
-    expect(result.details?.atoms_extracted).toBe(0);
-  });
-
  // v0.41.2.1 regression case (D9 #14 wording): with _pages:[] and same
  // _transcripts, all PRE-EXISTING PhaseResult.details fields match
  // pre-fix values byte-for-byte. The new fields (pages_processed,
@@ -43,135 +43,26 @@ describe('runExtractAtomsDrain (issue #1678)', () => {
    expect(batches).toBe(3);
  });

-  it('stops at the wallclock window; remaining is unknown (no post-window count)', async () => {
-    // Each batch consumes 60ms of the 100ms window: two batches fit, the
-    // third boundary check sees 120 ≥ 100 and stops. #2750: after the window
-    // elapses the final countRemaining is SKIPPED (it would overrun the
-    // window), so remaining reports null.
-    let now = 0;
+  it('stops at the wallclock window with remaining > 0', async () => {
+    // SYNC stepping clock: now() #1 sets deadline (0+100=100); the while-check
+    // then sees 50, 50 (two batches), then 999999 → past deadline → stop.
+    const times = [0, 50, 50, 999_999];
+    let ti = 0;
+    const now = () => times[Math.min(ti++, times.length - 1)];
    const result = await runExtractAtomsDrain(
      {
        withLock: passThroughLock,
        countRemaining: async () => 5, // never drains
-        runBatch: async () => {
-          now += 60;
-          return { extracted: 1, skipped: 0 };
-        },
-        now: () => now,
+        runBatch: async () => ({ extracted: 1, skipped: 0 }),
+        now,
      },
      { windowMs: 100 },
    );
    expect(result.stopped).toBe('window');
-    expect(result.remaining).toBeNull();
+    expect(result.remaining).toBe(5);
    expect(result.batches).toBe(2);
  });

-  it('passes one drain-level deadline signal into count and batch', async () => {
-    const seen: AbortSignal[] = [];
-    const controller = new AbortController();
-    let now = 0;
-    const result = await runExtractAtomsDrain(
-      {
-        withLock: passThroughLock,
-        countRemaining: async (signal) => {
-          seen.push(signal);
-          return 5;
-        },
-        runBatch: async (signal) => {
-          seen.push(signal);
-          now = 100;
-          return { extracted: 1, skipped: 0 };
-        },
-        now: () => now,
-      },
-      { windowMs: 100, abortSignal: controller.signal },
-    );
-    expect(result.stopped).toBe('window');
-    expect(result.batches).toBe(1);
-    expect(seen.length).toBe(2);
-    expect(seen[0]).toBe(seen[1]);
-    // Combined (timeout + external) signal, not the raw external one.
-    expect(seen[0]).not.toBe(controller.signal);
-  });
-
-  it('aborts a hung backlog count at the window deadline and releases the lock', async () => {
-    let released = false;
-    const result = await runExtractAtomsDrain(
-      {
-        withLock: async (work) => {
-          try { return await work(); }
-          finally { released = true; }
-        },
-        // Hangs until the drain's real-time deadline signal fires (10ms).
-        countRemaining: (signal) => new Promise((_resolve, reject) => {
-          signal.addEventListener('abort', () => reject(signal.reason), { once: true });
-        }),
-        runBatch: async () => ({ extracted: 0, skipped: 0 }),
-        now: () => 0, // injected clock never advances — the SIGNAL must save us
-      },
-      { windowMs: 10 },
-    );
-    expect(result.stopped).toBe('window');
-    expect(result.remaining).toBeNull();
-    expect(released).toBe(true);
-  });
-
-  it('rethrows external cancellation after releasing the lock', async () => {
-    const controller = new AbortController();
-    let released = false;
-    const pending = runExtractAtomsDrain(
-      {
-        withLock: async (work) => {
-          try { return await work(); }
-          finally { released = true; }
-        },
-        countRemaining: (signal) => new Promise((_resolve, reject) => {
-          signal.addEventListener('abort', () => reject(signal.reason), { once: true });
-        }),
-        runBatch: async () => ({ extracted: 0, skipped: 0 }),
-        now: () => 0,
-      },
-      { windowMs: 1_000_000, abortSignal: controller.signal },
-    );
-    controller.abort(new DOMException('worker timeout', 'AbortError'));
-    await expect(pending).rejects.toThrow('worker timeout');
-    expect(released).toBe(true);
-  });
-
-  it('classifies a deadline-exhausted zero-progress batch as window, not no_progress', async () => {
-    let now = 0;
-    const result = await runExtractAtomsDrain(
-      {
-        withLock: passThroughLock,
-        countRemaining: async () => 5,
-        runBatch: async () => {
-          now = 100; // batch consumed the whole window and returned nothing
-          return { extracted: 0, skipped: 0 };
-        },
-        now: () => now,
-      },
-      { windowMs: 100 },
-    );
-    expect(result.stopped).toBe('window');
-    expect(result.batches).toBe(1);
-  });
-
-  it('bounds a hung lock acquisition with the drain deadline signal', async () => {
-    const started = Date.now();
-    await expect(runExtractAtomsDrain(
-      {
-        withLock: (_work, signal) => new Promise((_resolve, reject) => {
-          signal.addEventListener('abort', () => reject(signal.reason), { once: true });
-        }),
-        countRemaining: async () => 1,
-        runBatch: async () => ({ extracted: 0, skipped: 0 }),
-        now: Date.now,
-      },
-      { windowMs: 10 },
-    )).rejects.toThrow();
-    expect(Date.now() - started).toBeLessThan(1_000);
-  });
-
  it('stops on a zero-progress batch (no hot loop)', async () => {
    let batches = 0;
    const result = await runExtractAtomsDrain(
@@ -242,17 +133,4 @@ describe('shared wiring helper holds the cycle lock (5A)', () => {
    expect(src).toContain('cycleLockIdFor(opts.sourceId)');
    expect(src).toContain('withRefreshingLock(engine, lockId');
  });
-
-  // #2750: the deadline signal must reach the phase, the backlog count, AND
-  // the lock wrapper — and the transcript path (brainDir) must stay wired
-  // exactly as the routine callers expect (PR #2752 takeover reverted its
-  // unsanctioned transcript-suppression scope change).
-  it('threads the drain deadline signal through phase, count, and lock', () => {
-    const jobsSrc = readFileSync(join(import.meta.dir, '../src/commands/jobs.ts'), 'utf8');
-    expect(src).toContain('abortSignal: signal');
-    expect(src).toContain('countExtractAtomsBacklog(engine, extractionSourceId, signal)');
-    expect(src).toContain('brainDir: opts.brainDir');
-    expect(src).not.toContain('_transcripts');
-    expect(jobsSrc).toContain('abortSignal: job.signal');
-  });
 });
@@ -304,7 +304,9 @@ describe('runExtractFacts — empty-fence guard (Codex R2-#7)', () => {
    expect(r.legacyRowsPending).toBe(1);
    expect(r.factsInserted).toBe(0);
    expect(r.factsDeleted).toBe(0);
-    expect(r.warnings.some(w => w.includes('apply-migrations'))).toBe(true);
+    // #1867: the remedy hint points at the re-runnable backfill command,
+    // not the one-shot v0_32_2 migration (which the ledger never re-runs).
+    expect(r.warnings.some(w => w.includes('gbrain facts fence-backfill'))).toBe(true);

    // Legacy row was NOT touched.
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -0,0 +1,133 @@
+/**
+ * #1867 — `gbrain facts fence-backfill` command tests.
+ *
+ * The command re-runs the (idempotent) v0_32_2 phase B on demand so
+ * row_num-NULL backlogs — remote extract_facts deposits that predate
+ * the fence-write backstop — can be cleared without re-running the
+ * one-shot migration. Real PGLite + real tempdir filesystem.
+ */
+
+import { describe, test, expect, beforeAll, afterAll, beforeEach } from 'bun:test';
+import { mkdtempSync, rmSync, existsSync, readFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+
+import { PGLiteEngine } from '../src/core/pglite-engine.ts';
+import { runFactsCommand } from '../src/commands/facts.ts';
+import { phaseBFenceFacts } from '../src/commands/migrations/v0_32_2.ts';
+
+let engine: PGLiteEngine;
+let brainDir: string;
+
+beforeAll(async () => {
+  engine = new PGLiteEngine();
+  await engine.connect({});
+  await engine.initSchema();
+});
+
+afterAll(async () => {
+  await engine.disconnect();
+  try {
+    if (brainDir) rmSync(brainDir, { recursive: true, force: true });
+  } catch { /* best-effort */ }
+});
+
+beforeEach(async () => {
+  brainDir = mkdtempSync(join(tmpdir(), 'facts-backfill-cmd-test-'));
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  await (engine as any).db.query('DELETE FROM facts');
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  await (engine as any).db.query(
+    `UPDATE sources SET local_path = $1 WHERE id = 'default'`,
+    [brainDir],
+  );
+});
+
+async function seedLegacyFact(fact: string): Promise<void> {
+  // The row_num-NULL shape a remote extract_facts deposit leaves behind
+  // when it lands via the legacy DB-only path.
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  await (engine as any).db.query(
+    `INSERT INTO facts (source_id, entity_slug, fact, kind, visibility, notability,
+                        valid_from, source, confidence)
+     VALUES ('default', 'people/alice', $1, 'fact', 'private', 'medium',
+             now(), 'mcp:extract_facts', 1.0)`,
+    [fact],
+  );
+}
+
+describe('gbrain facts fence-backfill', () => {
+  test('fences row_num-NULL rows and stamps the DB', async () => {
+    await seedLegacyFact('Deposited remotely');
+
+    await runFactsCommand(engine, ['fence-backfill']);
+
+    // The fence exists on disk with the claim.
+    const filePath = join(brainDir, 'people/alice.md');
+    expect(existsSync(filePath)).toBe(true);
+    expect(readFileSync(filePath, 'utf-8')).toContain('Deposited remotely');
+
+    // The backlog is cleared: no row_num-NULL rows remain.
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const rows = await (engine as any).db.query(
+      'SELECT row_num, source_markdown_slug FROM facts',
+    );
+    expect(rows.rows).toHaveLength(1);
+    expect(rows.rows[0].row_num).toBe(1);
+    expect(rows.rows[0].source_markdown_slug).toBe('people/alice');
+  });
+
+  test('re-run is a no-op (idempotent)', async () => {
+    await seedLegacyFact('Deposited remotely');
+    await runFactsCommand(engine, ['fence-backfill']);
+    await runFactsCommand(engine, ['fence-backfill']);
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const rows = await (engine as any).db.query('SELECT id FROM facts');
+    expect(rows.rows).toHaveLength(1);
+    const body = readFileSync(join(brainDir, 'people/alice.md'), 'utf-8');
+    expect(body.match(/Deposited remotely/g)).toHaveLength(1);
+  });
+
+  test('--dry-run reports without writing', async () => {
+    await seedLegacyFact('Deposited remotely');
+    await runFactsCommand(engine, ['fence-backfill', '--dry-run']);
+
+    expect(existsSync(join(brainDir, 'people/alice.md'))).toBe(false);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const rows = await (engine as any).db.query(
+      'SELECT row_num FROM facts',
+    );
+    expect(rows.rows[0].row_num).toBeNull();
+  });
+
+  test('diverged page: appends past the DB row_num max instead of colliding (#2044 class)', async () => {
+    // The #2044 divergence shape the backfill must survive: the DB already
+    // holds stamped rows 1..3 for the slug (legacy wrong-path fence write),
+    // but the fence at the resolved path is missing. Fence-max+1 (= 1) would
+    // collide with the stamped rows on the post-rename UPDATE, failing the
+    // page and leaving the renamed fence disagreeing with the DB.
+    for (let n = 1; n <= 3; n++) {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      await (engine as any).db.query(
+        `INSERT INTO facts (source_id, entity_slug, fact, kind, visibility, notability,
+                            valid_from, source, confidence, row_num, source_markdown_slug)
+         VALUES ('default', 'people/alice', $1, 'fact', 'private', 'medium',
+                 now(), 'mcp:extract_facts', 1.0, $2, 'people/alice')`,
+        [`stamped ${n}`, n],
+      );
+    }
+    await seedLegacyFact('Deposited remotely');
+
+    const result = await phaseBFenceFacts(engine, { dryRun: false });
+    expect(result.status).toBe('complete');
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const rows = await (engine as any).db.query(
+      `SELECT row_num FROM facts WHERE fact = 'Deposited remotely'`,
+    );
+    expect(rows.rows[0].row_num).toBe(4);
+    const body = readFileSync(join(brainDir, 'people/alice.md'), 'utf-8');
+    expect(body).toContain('| 4 | Deposited remotely |');
+  });
+});
@@ -292,6 +292,49 @@ describe('lookupSourceLocalPath', () => {
  });
 });

+describe('writeFactsToFence — fence/DB divergence (#2044)', () => {
+  test('seeds row_num past the DB max when the fence lags the DB', async () => {
+    // Simulate the divergence class from #2044: DB rows were stamped with
+    // row_nums against a fence written at a path this code no longer reads
+    // (e.g. the pre-"Local patch 2026-06-11" wrong-path writes). The page
+    // on disk has NO fence, but the DB already holds row_num 1..3 for the
+    // slug. Pre-fix, the next deposit re-assigned row_num=1 from fence
+    // text alone and the whole insertFacts batch failed on
+    // idx_facts_fence_key.
+    for (let n = 1; n <= 3; n++) {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      await (engine as any).db.query(
+        `INSERT INTO facts (source_id, entity_slug, fact, kind, visibility, notability,
+                            valid_from, source, confidence, row_num, source_markdown_slug)
+         VALUES ('default', 'people/dana', $1, 'fact', 'private', 'medium',
+                 now(), 'mcp:extract_facts', 1.0, $2, 'people/dana')`,
+        [`old claim ${n}`, n],
+      );
+    }
+
+    const result = await writeFactsToFence(
+      engine,
+      { sourceId: 'default', localPath: brainDir, slug: 'people/dana' },
+      [baseInput({ fact: 'second deposit' })],
+    );
+
+    expect(result.fenceWriteFailed).toBeUndefined();
+    expect(result.inserted).toBe(1);
+
+    // The new row landed PAST the DB max, not at fence-max+1 (= 1).
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const rows = await (engine as any).db.query(
+      'SELECT row_num FROM facts WHERE id = $1',
+      [result.ids[0]],
+    );
+    expect(rows.rows[0].row_num).toBe(4);
+
+    // And the on-disk fence carries the same row_num — fence and DB agree.
+    const body = readFileSync(join(brainDir, 'people/dana.md'), 'utf-8');
+    expect(body).toContain('| 4 | second deposit |');
+  });
+});
+
 // Cleanup any leftover tempdirs after the whole suite.
 afterAll(() => {
  // No-op: each test cleaned up via the beforeEach; this is a safety net.
@@ -24,18 +24,15 @@ import type { BrainEngine } from '../../src/core/engine.ts';
 // Mock engine: healthCheck() calls engine.executeRaw; return empty rows so
 // the query path exercises without needing Postgres.
 //
-// #1849: start() acquires the queue-scoped DB singleton lock via
-// tryAcquireDbLock. #2750 routed the acquire upsert through engine.executeRaw
-// (signal-boundable) and release through engine.executeRawDirect, so the
-// stub returns a single row from the lock upsert (length 1 → acquired) and
-// empty rows everywhere else. Each spawned runner is a fresh process, so
-// there's no cross-test lock state to clean up.
+// #1849: start() now acquires the queue-scoped DB singleton lock via
+// tryAcquireDbLock, which uses the postgres `sql` tagged-template escape hatch.
+// The stub returns a single row from every call so acquire succeeds (length 1
+// → acquired) and refresh/release are no-ops. Each spawned runner is a fresh
+// process, so there's no cross-test lock state to clean up.
 const sqlStub = (..._args: unknown[]) => Promise.resolve([{ id: 'supervisor-lock' }]);
 const mockEngine: Partial<BrainEngine> = {
  kind: 'postgres' as const,
-  executeRaw: async (query: string) =>
-    query.includes('gbrain_cycle_locks') ? [{ id: 'supervisor-lock' }] : [],
-  executeRawDirect: async () => [],
+  executeRaw: async () => [],
  sql: sqlStub,
 } as unknown as BrainEngine;

@@ -5,7 +5,7 @@
 *   - Batch insert N rows persists row_num + source_markdown_slug
 *   - Empty batch is a no-op
 *   - Returns ids in input-order
- *   - v51 partial UNIQUE index rolls back the whole batch on a collision
+ *   - v51 partial UNIQUE collision skips only the colliding row (#2044)
 *   - deleteFactsForPage scopes by (source_id, source_markdown_slug);
 *     never touches other pages or pre-v51 NULL-source_markdown_slug rows
 *   - deleteFactsForPage on an empty page returns deleted:0 (idempotent)
@@ -135,30 +135,29 @@ describe('engine.insertFacts — batch insert', () => {
    });
  });

-  test('v51 partial UNIQUE index rolls back the whole batch on collision', async () => {
+  test('v51 partial UNIQUE collision skips ONLY the colliding row (#2044)', async () => {
    // Seed row #1 first.
    await engine.insertFacts([fixtureFact(1, { fact: 'seeded' })], { source_id: 'default' });

-    // Now try to batch-insert rows that include a colliding row_num=1.
-    let threw = false;
-    try {
-      await engine.insertFacts(
-        [
-          fixtureFact(2, { fact: 'second' }),
-          fixtureFact(1, { fact: 'collides' }),  // row_num=1 on same (source_id, source_markdown_slug)
-          fixtureFact(3, { fact: 'third' }),
-        ],
-        { source_id: 'default' },
-      );
-    } catch {
-      threw = true;
-    }
-    expect(threw).toBe(true);
+    // Batch-insert rows that include a colliding row_num=1. Pre-#2044 this
+    // threw and rolled back the whole batch, making a second remote
+    // extract_facts deposit to an already-fenced page a hard failure. Now
+    // ON CONFLICT DO NOTHING skips the colliding row and keeps the rest.
+    const result = await engine.insertFacts(
+      [
+        fixtureFact(2, { fact: 'second' }),
+        fixtureFact(1, { fact: 'collides' }),  // row_num=1 on same (source_id, source_markdown_slug)
+        fixtureFact(3, { fact: 'third' }),
+      ],
+      { source_id: 'default' },
+    );
+    expect(result.inserted).toBe(2);
+    expect(result.ids).toHaveLength(2);

-    // Verify the transaction rolled back — only the seeded row should remain.
+    // The seeded row survives untouched; the colliding claim is skipped.
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    const rows = await (engine as any).db.query('SELECT fact FROM facts ORDER BY id');
-    expect(rows.rows.map((r: { fact: string }) => r.fact)).toEqual(['seeded']);
+    expect(rows.rows.map((r: { fact: string }) => r.fact)).toEqual(['seeded', 'second', 'third']);
  });

  test('different source_markdown_slug values DO NOT collide on the same row_num', async () => {
@@ -98,39 +98,14 @@ describe('PostgresEngine.executeRawDirect — routing decision (PR #1816)', () =
  });

  test('already-aborted signal short-circuits with AbortError before routing the query', async () => {
-    let unsafeCalls = 0;
-    let ddlCalls = 0;
-    const readConn: FakeSql = { unsafe: async () => { unsafeCalls++; return []; } };
+    const readConn = fakeSql('read');
    const directConn = fakeSql('direct');
    const engine = makeEngine({ dualPoolActive: true, readConn, directConn });
-    const e = engine as unknown as { connectionManager: { ddl: () => Promise<FakeSql> } };
-    e.connectionManager.ddl = async () => { ddlCalls++; return directConn; };

    const ac = new AbortController();
    ac.abort();
    await expect(
      engine.executeRawDirect('UPDATE minion_jobs SET x=1', [], { signal: ac.signal }),
    ).rejects.toThrow(/abort/i);
-    // #2750: short-circuits BEFORE pool routing — no ddl(), no unsafe().
-    expect(ddlCalls).toBe(0);
-    expect(unsafeCalls).toBe(0);
-  });
-
-  test('#2750: signal bounds a stalled direct-pool acquisition before unsafe starts', async () => {
-    let unsafeCalls = 0;
-    const readConn: FakeSql = { unsafe: async () => { unsafeCalls++; return []; } };
-    const directConn = fakeSql('direct');
-    const engine = makeEngine({ dualPoolActive: true, readConn, directConn });
-    const e = engine as unknown as { connectionManager: { ddl: () => Promise<FakeSql> } };
-    e.connectionManager.ddl = () => new Promise<FakeSql>(() => {}); // pooler exhausted: never resolves
-
-    const started = Date.now();
-    await expect(engine.executeRawDirect(
-      'DELETE FROM gbrain_cycle_locks',
-      [],
-      { signal: AbortSignal.timeout(10) },
-    )).rejects.toThrow(/abort/i);
-    expect(Date.now() - started).toBeLessThan(1_000);
-    expect(unsafeCalls).toBe(0);
  });
 });