feat(01-14): monitorTypeSurfaces:'include' — narrow picker to monitor surfaces only

[per Plan 01-14; closes B-01-14-01 via Step 1b lockstep]

- src/offscreen/recorder.ts: add monitorTypeSurfaces:'include' as top-level
  DisplayMediaStreamOptions sibling of video: (W3C Screen Capture spec §6.1;
  Chrome >= 119; removes tab/window panes from the operator's picker per
  Plan 01-10 RESEARCH §5 + §Pitfall-5 recommendation). Typed widening cast
  extended in lockstep to keep the explicit-typing contract (no `as any`).
  D-15 post-grant validation block at recorder.ts:294 UNCHANGED — belt
  (picker narrowing) + suspenders (post-grant tear-down) chain preserved.

- tests/offscreen/display-surface-constraint.test.ts: lockstep update of
  the strict-deep-equality assertion at lines 223-226 with the same key
  ordering as the source change (video -> monitorTypeSurfaces -> audio).
  toHaveBeenCalledWith contract preserved (NO expect.objectContaining —
  the test author's "catches future drops of ANY field" discipline is
  honored). This edit + the source change land in the SAME commit so the
  98/98 baseline never crosses a commit boundary in RED state.

- src/test-hooks/offscreen-hooks.ts: capture last constraints object in
  module-scoped `lastGetDisplayMediaConstraints` cell (was `_constraints`
  received-but-unused; renamed to `constraints`); add `get-last-getDisplayMedia-constraints`
  bridge op to the __mokoshOffscreenQuery dispatcher between
  get-display-surface and get-segment-count. Defensive try/catch mirrors
  the existing dispatcher pattern; the cell is module-internal so the
  MokoshTestSurface cross-cast in types.ts requires NO change (decision
  documented inline in offscreen-hooks.ts).

- tests/uat/extension-page-harness.ts: add `assertA23` mirroring `assertA3`
  (bridge query → 2-check AssertionResult: non-null constraints + value).
  Extend the `Window.__mokoshHarness` declaration + runtime export + status
  bar text + console.log to reference A23.

- tests/uat/lib/harness-page-driver.ts: export `driveA23(page)` mirroring
  the `driveA14` page.evaluate wrapper shape. Standard read-only driver.

- tests/uat/harness.test.ts: extend FORBIDDEN_HOOK_STRINGS (line 85) with
  `lastGetDisplayMediaConstraints` and `get-last-getDisplayMedia-constraints`.
  Import driveA23. Append `{ name: 'A23', drive: driveA23 }` to the drivers
  array after the A14 entry. Update header comment + orchestrator stdout
  to reflect A14 + A23 chain. The `Total = drivers.length + 1` arithmetic
  adapts automatically: 14 + 1 = 15 → 15 + 1 = 16.

- tests/background/no-test-hooks-in-prod-bundle.test.ts: lockstep
  extension of FORBIDDEN_HOOK_STRINGS (line 105) with the same 2 strings.
  Header comment updated to "Total: 12 surface strings." (was 10).
  Confirms production `dist/` has ZERO occurrences after `npm run build`
  via the `__MOKOSH_UAT__` dead-branch tree-shake (T-01-14-04 mitigation).

D-01 (whole-desktop only via getDisplayMedia; reject window/tab surfaces) is
the design intent that monitorTypeSurfaces:'include' realizes at the picker-
UI level. D-15 post-grant validation (recorder.ts:294-307) remains the
actual enforcement against managed-policy/DevTools/older-Chrome overrides.

Verification chain (per Plan 01-14 §verify; clean post-commit):
- `npx tsc --noEmit` exit 0
- `npm run build` exit 0; dist/ produced, monitorTypeSurfaces ships in
  the offscreen chunk as the operator-facing picker hint
- `npm run build:test` exit 0; dist-test/ produced with the harness
  hooks intact (gated)
- `npm test` 100/100 GREEN (was 98/98; +2 via the 2 new FORBIDDEN_HOOK_STRINGS
  parametrized tests — both PASS, production bundle hook-free)
- `npm run test:uat` 16/16 GREEN (15 → 16 via A23). A23 reads constraints
  `{video: {...}, monitorTypeSurfaces: 'include', audio: false}` from the
  fakeGetDisplayMedia capture cell — round-trips through the full call site.
- Production bundle spot-check:
    `grep -rc 'lastGetDisplayMediaConstraints\|get-last-getDisplayMedia-constraints' dist/ | grep -v ':0$'`
    → empty (all `:0` filtered) → ZERO leakage.

References:
- W3C Screen Capture §6.1 DisplayMediaStreamOptions:
  https://www.w3.org/TR/screen-capture/#dom-displaymediastreamoptions-monitortypesurfaces
- Chrome screen-sharing-controls (Chrome 119+):
  https://developer.chrome.com/docs/web-platform/screen-sharing-controls
- Plan 01-10 RESEARCH §5 + §Pitfall-5 (recommendation provenance):
  .planning/phases/01-stabilize-video-pipeline/01-10-RESEARCH.md
- Architectural-note (replaces retired AMENDMENT-A.md improvisation per
  01-11-SUMMARY): canonical GSD ceremony — plan → checker (B-01-14-01)
  → executor → SUMMARY (this commit).

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

src/test-hooks/offscreen-hooks.ts

@@ -99,6 +99,22 @@ let fakeCanvas: HTMLCanvasElement | null = null;
 let fakeAnimationHandle: number | null = null;
 let fakeDrawInterval: ReturnType<typeof setInterval> | null = null;
 
+/**
+ * Plan 01-14 A23 contract — record the last-received constraints object
+ * from every `fakeGetDisplayMedia` invocation. The `installFakeDisplayMedia`
+ * shim already accepts the `constraints` parameter (previously prefixed
+ * `_constraints` as received-but-unused — see below), so the production
+ * call site's `monitorTypeSurfaces: 'include'` sibling lands here. The
+ * `get-last-getDisplayMedia-constraints` bridge op (later in this file)
+ * reads it for harness inspection.
+ *
+ * `null` until any `getDisplayMedia` call has been made — A23 always
+ * runs AFTER A2's `setupFreshRecording` so the cell is populated by
+ * then. Test bundle only; gated identically to the rest of this module
+ * by the top-of-module `__MOKOSH_UAT__` import in src/offscreen/recorder.ts.
+ */
+let lastGetDisplayMediaConstraints: DisplayMediaStreamOptions | null = null;
+
 /**
  * Replace `navigator.mediaDevices.getDisplayMedia` with a synthetic
  * implementation backed by a hidden 30 fps canvas. The returned
@@ -233,8 +249,13 @@ export function installFakeDisplayMedia(): void {
   // straight assignment would trip the type checker. The runtime
   // dispatch ignores arguments entirely — fake stream regardless.
   const fakeGetDisplayMedia = async (
-    _constraints?: DisplayMediaStreamOptions,
+    constraints?: DisplayMediaStreamOptions,
   ): Promise<MediaStream> => {
+    // Plan 01-14 A23: capture the production call's constraints object
+    // so the harness can verify `monitorTypeSurfaces: 'include'` reached
+    // the call site. Default to null on undefined-args so the bridge op
+    // reports an unambiguous "no args" signal rather than `undefined`.
+    lastGetDisplayMediaConstraints = constraints ?? null;
     return mintStream();
   };
   (navigator.mediaDevices as unknown as {
@@ -355,6 +376,14 @@ globalThis.__mokoshTest = {
 //       zero count is meaningful. The 10s rotation cadence (D-13;
 //       SEGMENT_DURATION_MS) means a recording that has been live for
 //       ~35s should report count ≥ 3 (3 × 10s = 30s = MAX_SEGMENTS).
+//   op='get-last-getDisplayMedia-constraints' → { constraints: object|null }
+//     — Plan 01-14 A23 contract. Returns the most-recent constraints
+//       object captured by `fakeGetDisplayMedia`. Used by the harness to
+//       verify the production call site passes `monitorTypeSurfaces: 'include'`
+//       (W3C Screen Capture spec §6.1; Chrome ≥ 119 picker-narrowing
+//       semantics). `null` only when no getDisplayMedia call has happened
+//       yet — A23 always runs AFTER A2's setupFreshRecording so a non-null
+//       value is the expected case.
 // Unknown ops respond { ok: false, error: 'unknown-op' }.
 //
 // The bridge handler MUST run BEFORE the production offscreen bridge
@@ -433,6 +462,34 @@ chrome.runtime.onMessage.addListener((rawMessage, _sender, sendResponse) => {
     }
     return false;
   }
+  if (op === 'get-last-getDisplayMedia-constraints') {
+    // Plan 01-14 A23 contract — return the most-recent constraints object
+    // captured by the `fakeGetDisplayMedia` shim. Production code at
+    // src/offscreen/recorder.ts:270 calls `navigator.mediaDevices.getDisplayMedia({
+    // video: {...}, monitorTypeSurfaces: 'include', audio: false })`; this op
+    // exposes that object so the harness can assert
+    // `constraints.monitorTypeSurfaces === 'include'`.
+    //
+    // `null` is returned in two cases:
+    //   (a) No `getDisplayMedia` call has been made yet — A23 always runs
+    //       AFTER A2's setupFreshRecording so this is unreachable in the
+    //       orchestrated sequence;
+    //   (b) The call was made with `undefined` args — also unreachable for
+    //       the production call site which always supplies the constraints
+    //       object.
+    // try/catch is defensive — bridge handlers must never propagate
+    // exceptions to chrome.runtime.sendMessage (the dispatcher contract
+    // shared by all ops above).
+    try {
+      sendResponse({ constraints: lastGetDisplayMediaConstraints });
+    } catch (err) {
+      sendResponse({
+        ok: false,
+        error: err instanceof Error ? err.message : String(err),
+      });
+    }
+    return false;
+  }
   if (op === 'get-segment-count') {
     // Plan 01-13 Wave 3D A11 contract — return the offscreen recorder's
     // live segment count via the `segmentCountGetter` closure wired at