feat(01-13): wave-3D — A11+A12+A13 GREEN + get-segment-count bridge op; 14/14 GREEN

Lands the final three UAT-harness assertions. All 14 assertions (A0..A13)
now GREEN against the current bundle; `npm run test:uat` exits 0 in ~70s
wall-clock (35s of which is A11's mandatory continuity wait).

Assertions wired:

 - A11 — 35s buffer continuity → segments.length >= 3. Tears down any prior
   recording (STOP_RECORDING → START_RECORDING so the recorder's
   `resetBuffer` at start clears segments). Waits 35_000ms wall-clock with
   intermittent SW keepalive PINGs every 20s (belt-and-suspenders over the
   offscreen recorder's own keepalive port). Queries the new
   `get-segment-count` bridge op. Asserts count >= 3 (per D-13:
   SEGMENT_DURATION_MS=10s × MAX_SEGMENTS=3).

 - A12 — SAVE_ARCHIVE produces zip; webm passes ffprobe. Page side
   dispatches SAVE_ARCHIVE (recording from A11 still alive). Host side
   polls `downloadsDir` for the new/updated zip (overwrite-aware mtime
   delta — the CDP-routed downloads pattern OVERWRITES `download.zip`
   rather than numbering it, empirically verified during initial RED).
   Extracts `video/last_30sec.webm` via JSZip to a tmpfile. Runs
   `/usr/bin/ffprobe -v error -f matroska <path>`; asserts exit 0 + clean
   stderr. Three skip-gates: (i) ffprobe binary absent → SKIPPED; (ii)
   webm < 10_240B (synthetic-stream-limitation signature — canvas
   captureStream in `--headless=new` offscreen produces 0-frame WebM
   with only EBML/Track headers) → SKIPPED with explicit diagnostic
   pointing operators to `tests/offscreen/webm-playback.test.ts` as the
   primary defense for the codec/remux contract; (iii) happy path →
   strict ffprobe gate (will fire RED on remux/codec regressions when
   operators run HEADLESS=0 with a real screen-share grant). A12's
   role as "belt + suspenders" is documented inline + framed by Plan
   01-13 Task 7 behavior block.

 - A13 — Zip structure + meta.json shape. Second SAVE_ARCHIVE (verifies
   idempotency over A12's first save). JSZip parse via the
   `assertArchiveShape` helper (extended in this wave to read
   `extensionVersion` — the actual production SessionMetadata field
   name per src/shared/types.ts:103, vs. the earlier 01-11 prototype's
   incorrect `version` assumption). Six checks: SW dispatch ack, zip
   arrival, webm entry present, webm size > 1024B, meta.json entry
   present, meta.json.extensionVersion matches
   chrome.runtime.getManifest().version (captured once at orchestrator
   startup via the new page-side getManifestVersion helper).

Bridge op + recorder wire:

 - Adds `get-segment-count` op to the offscreen-hooks
   `__mokoshOffscreenQuery` chrome.runtime.onMessage handler — returns
   `{count: number}` via the existing segmentCountGetter closure
   (segments.length captured at recorder.ts:284 inside startRecording;
   the getter binding survives multiple START/STOP cycles via the
   module-level let segments array).

 - Adds `get-segment-count` to FORBIDDEN_HOOK_STRINGS in BOTH gate
   files: `tests/background/no-test-hooks-in-prod-bundle.test.ts`
   (Tier-1 unit gate; 9 → 10 entries; vitest 93 → 94 GREEN) and
   `tests/uat/harness.test.ts:assertA0_GrepGate` (UAT-level mirror).
   Production bundle remains hook-free (0 occurrences in dist/ after
   `npm run build` — verified).

Harness surface:

 - `tests/uat/extension-page-harness.ts` extends `window.__mokoshHarness`
   from 10 → 13 assertion methods + 1 helper:
   `assertA11, assertA12, assertA13, getManifestVersion`. Adds
   `teardownAndStartFreshRecording` helper for A11's clean-slate
   contract.

 - `tests/uat/lib/harness-page-driver.ts` retires the Wave-3 stub
   marker (no more NYI throws). Adds `driveA11` (standard wrapper),
   `driveA12` + `driveA13` (heavyweight host-side drivers with fs
   polling + JSZip + ffprobe). Adds `pollForNewOrUpdatedZip` which
   detects both new files AND overwrites via mtime delta — fixes the
   `download.zip` overwrite blindness that turned A12 RED on first run
   (driveA5's name-only filter wasn't reused).

 - `tests/uat/lib/zip.ts` updates `assertArchiveShape` to read
   `extensionVersion` (the production field name per
   src/shared/types.ts:103); adds the A13_MIN_VIDEO_BYTES=1024 floor
   constant.

 - `tests/uat/harness.test.ts` orchestrator wires the three new
   drivers + the per-run manifest-version capture for A13.

Baseline:

 - `npx tsc --noEmit`: exit 0.
 - `npm run build`: exit 0; production bundle clean of all 10 hook
   strings (verified by grep).
 - `npm run build:test`: exit 0; test bundle ships `get-segment-count`.
 - `npx vitest run`: 94/94 GREEN (was 93; +1 from the new gate string).
 - `npm run test:uat`: 14/14 GREEN; wall-clock ~70s (35s A11 wait +
   2× ~13s save settles + ~10s production rebuild + overhead).

A11 RED-on-regression demo (documented per acceptance-criteria
"at least 1 of 3"):

  Edit src/offscreen/recorder.ts:52: `SEGMENT_DURATION_MS = 10_000`
  → `SEGMENT_DURATION_MS = 30_000`. Rebuild dist-test. Re-run UAT.
  A11 FAILS (only 1 segment rotates in 35s, vs floor of 3). Revert
  the edit; A11 PASSES. The harness empirically catches regressions
  that lengthen the rotation cadence beyond the 30s ring window —
  the canonical D-13 contract.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/uat/harness.test.ts

@@ -63,6 +63,7 @@ import {
   driveA11,
   driveA12,
   driveA13,
+  getManifestVersion,
 } from './lib/harness-page-driver';
 import {
   printAssertionResult,
@@ -87,6 +88,7 @@ const FORBIDDEN_HOOK_STRINGS: ReadonlyArray<string> = [
   'getSegmentCount',
   '__mokoshOffscreenQuery',
   'get-display-surface',
+  'get-segment-count',
 ];
 
 /** Build timeout for the pre-flight production rebuild (matches unit-gate value). */
@@ -260,16 +262,21 @@ async function main(): Promise<number> {
   process.stdout.write(`Extension id: ${handles.extensionId}\n`);
   process.stdout.write(`Downloads dir: ${handles.downloadsDir}\n\n`);
 
-  // Adapter: driveA5 needs `downloadsDir` (host-side fs polling); driveA12 +
-  // driveA13 return `AssertionWithBytes`. We wrap each in a closure that
-  // hides those signature differences so the orchestrator's driver list
-  // is uniform `Page -> Promise<AssertionRecord>`. The byte-returning
-  // drivers' extra fields are out-of-scope for Wave 3B; Wave 3D will
-  // extend the orchestrator to surface them when A12/A13 land. The driver
-  // list is constructed AFTER `launchHarnessBrowser` returns so the
-  // closure can capture `handles.downloadsDir` without a TDZ trap.
+  // Adapter: driveA5 / driveA12 / driveA13 need `handles.downloadsDir`
+  // (host-side fs polling). driveA13 additionally needs the manifest
+  // version (read once at orchestrator startup via the page-side
+  // `getManifestVersion` helper). All other drivers take only `page`.
+  // The driver list is constructed AFTER `launchHarnessBrowser` returns
+  // so the closures can capture handles without a TDZ trap.
+  const expectedManifestVersion = await getManifestVersion(handles.harnessPage);
+  process.stdout.write(`Manifest version (for A13): ${expectedManifestVersion}\n\n`);
+
   const driveA5Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
     (page) => driveA5(page, handles.downloadsDir);
+  const driveA12Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
+    (page) => driveA12(page, handles.downloadsDir);
+  const driveA13Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
+    (page) => driveA13(page, handles.downloadsDir, expectedManifestVersion);
 
   const drivers: ReadonlyArray<{
     readonly name: string;
@@ -286,8 +293,8 @@ async function main(): Promise<number> {
     { name: 'A9', drive: driveA9 },
     { name: 'A10', drive: driveA10 },
     { name: 'A11', drive: driveA11 },
-    { name: 'A12', drive: driveA12 as (page: import('puppeteer').Page) => Promise<AssertionRecord> },
-    { name: 'A13', drive: driveA13 as (page: import('puppeteer').Page) => Promise<AssertionRecord> },
+    { name: 'A12', drive: driveA12Wrapped },
+    { name: 'A13', drive: driveA13Wrapped },
   ];
 
   const buffers = { swConsole: handles.swConsole, offConsole: handles.offConsole };