# Phase 3: SPEC §10 smoke verification + DOM/event-log verification - Pattern Map

**Mapped:** 2026-05-20
**Files analyzed:** 5 anticipated (4 modifications + 1 new VERIFICATION.md) + optional 6th (Page.metrics scaffolding)
**Analogs found:** 5 / 5 (4 exact, 1 role-match; +1 partial for optional Page.metrics)
**Phase character:** Verification-heavy; Approach B harness extension (Plan 02-04 is direct precedent for 4 of 5 files).

## File Classification

| Anticipated File (Plans 03-01..05) | Role | Data Flow | Closest Analog | Match Quality |
|-------------------------------------|------|-----------|----------------|---------------|
| `tests/uat/extension-page-harness.ts` (page-side `assertA29..A3X`) | test (page-side assertion host) | request-response (chrome.runtime.sendMessage round-trip) + event-driven (chrome.downloads.onCreated listener for A24 echo, if needed by Plan 03-02) | `tests/uat/extension-page-harness.ts:2851-3413` (assertA24..assertA28 block; Plan 02-04) | EXACT (same file; append-only) |
| `tests/uat/lib/harness-page-driver.ts` (host-side `driveA29..A3X` + `JSZip` reads) | test (host-side driver + zip inspection) | file-I/O (downloadsDir polling + JSZip-parse) + request-response (page.evaluate wrapper) | `tests/uat/lib/harness-page-driver.ts:1202-1849` (driveA24..driveA28 + `findLatestZip` + `A28_EXPECTED_PATHS`; Plan 02-04) | EXACT (same file; append-only) |
| `tests/uat/harness.test.ts` (orchestrator wiring: imports + wrapped drivers + drivers array push + banner) | test (orchestrator) | request-response (sequential driver dispatch + bail-on-first-failure) | `tests/uat/harness.test.ts:93-99 + 316-335 + 406-430` (driveA24-A28 imports + wrappers + push; Plan 02-04) | EXACT (same file; append-only) |
| `tests/uat/extension-page-harness.html` (probe HTML append) | test (DOM scaffold) | static markup | `tests/uat/extension-page-harness.html:17-22` (existing `<h1>` + `<pre id="status">`; Plan 01-12 Wave 6 tokens.css preserved) | EXACT (same file; append-only) |
| `.planning/phases/03-.../03-VERIFICATION.md` (NEW; aggregator) | docs (verification aggregator with frontmatter) | docs synthesis | `.planning/phases/02-stabilize-export-pipeline/02-VERIFICATION.md` (T5 override pattern; 5/5 must-haves; Plan 02-04 closure) PLUS `.planning/phases/01-stabilize-video-pipeline/01-VERIFICATION.md` (per-requirement scorecard; cross-cutting gates table; operator empirical acks; deferred items section) | EXACT (T5 override) + ROLE-MATCH (scorecard structure) |
| `tests/uat/lib/ramMetrics.ts` OR inline in `harness-page-driver.ts` (OPTIONAL — D-P3-04 best-effort `puppeteer.Page.metrics()` scaffolding) | test (host-side utility) | request-response (CDP `Performance.getMetrics` via `Page.metrics()`) | NONE (research-derived; no existing analog) — closest scaffolding shape lives in `tests/uat/lib/harness-page-driver.ts:1255-1334` (driveA25 host-side latency measurement + diagnostic copy pattern) | NEW PATTERN (cite RESEARCH §"Code Examples" A3X) |

## Pattern Assignments

### `tests/uat/extension-page-harness.ts` (page-side `assertA29..A3X` for Plans 03-01..04)

**Analog:** `tests/uat/extension-page-harness.ts:2851-3413` (Plan 02-04 assertA24-A28)

**Existing imports / module context** — already present at top of file; no new imports expected:
- The harness uses ambient chrome.* types (`chrome.downloads.DownloadItem`, `chrome.tabs.create`, etc.); production surfaces only.
- Helper utilities `setupFreshRecording`, `sendMessageWithTimeout`, `diag` (file-local) — all reusable for Plan 03-01..04.

**Module constants block** — Plan 02-04 precedent for per-assertion tuning constants (lines 2977-2982):

```typescript
/** SAVE_ARCHIVE dispatch timeout for A25 — matches A24's 15s. */
const A25_SAVE_ARCHIVE_TIMEOUT_MS = 15_000;
/** Pre-SAVE segment-settle window (10s rotation + 1s slack). */
const A25_SEGMENT_SETTLE_MS = 11_000;
/** Hard latency ceiling per SPEC §10 #6 + CON-archive-export-latency. */
const A25_LATENCY_CEILING_MS = 5_000;
```

Phase 3 plans should follow the same `const A<NN>_<PURPOSE>_MS = NNNN_NNN;` form (`A29_SEGMENT_SETTLE_MS`, `A30_TRIGGER_PAUSE_MS`, `A31_PASSWORD_SENTINEL`, etc.).

**Page-side stub pattern (for host-side-only work)** — `assertA26` lines 3164-3173 + `assertA28` lines 3307-3316:

```typescript
/**
 * A26 — D-P2-02 + D-P2-03 empirical (page-side stub).
 *
 * Returns the assertion name + a sentinel diagnostic. All real work
 * happens host-side in driveA26 (JSZip-parse the latest zip + assert
 * meta.json shape). The page-side stub exists purely so the orchestrator's
 * single-method-per-assertion contract (window.__mokoshHarness.assertA26)
 * is uniform across all 29 assertions.
 *
 * Chaining: A26 reads the zip produced by A25 (host-side driver picks
 * the most-recently-modified zip in downloadsDir). No new SAVE dispatch.
 *
 * @returns Stub AssertionResult with empty checks; driveA26 fills them.
 */
async function assertA26(): Promise<AssertionResult> {
  return {
    passed: true,
    name: 'A26 — meta.json 8-field shape (D-P2-02 + D-P2-03)',
    checks: [],
    diagnostics: [
      'assertA26 page-side stub; host-side driveA26 inspects latest zip + asserts meta.json shape',
    ],
  };
}
```

**Use for:** Plan 03-01 (rrweb session.json inspection is host-side JSZip), Plan 03-02 (events.json grep is host-side), Plan 03-03 (sentinel grep is host-side). Page-side stubs for A29 / A30 / A31; host-side drivers do the work.

**Page-side orchestration pattern (when chrome.* APIs are required pre-SAVE)** — `assertA24` lines 2851-2962 (chrome.downloads.onCreated cross-realm capture) and `assertA27` lines 3202-3292 (chrome.tabs.create + activate + cleanup):

```typescript
async function assertA24(): Promise<AssertionResult> {
  const result: AssertionResult = {
    passed: false,
    name: 'A24 — D-P2-01 empirical: chrome.downloads.download receives blob: URL (closes P0-6)',
    checks: [],
    diagnostics: [],
  };

  // Capture stored in closure so the onCreated listener can populate it
  // across the async SAVE_ARCHIVE dispatch + post-ack poll.
  let capturedUrl: string | null = null;
  let listenerInstalled = false;
  const onCreatedListener = (item: chrome.downloads.DownloadItem): void => {
    if (capturedUrl === null) {
      capturedUrl = item.url;
    }
  };

  try {
    diag(result, 'Step 1: setupFreshRecording (A24 owns its recording — onCreated listener installed pre-SAVE)');
    const setupResp = await setupFreshRecording();
    if (!setupResp.ok) {
      throw new Error(`setupFreshRecording failed: ${setupResp.error ?? '(no error)'}`);
    }
    // ... Step 2: settle, Step 3: install listener, Step 4: dispatch SAVE_ARCHIVE, Step 5: poll for capturedUrl
  } catch (err) {
    result.error = err instanceof Error ? err.message : String(err);
    diag(result, `THREW: ${result.error}`);
  } finally {
    // T-02-04-01 mitigation: always remove the listener (idempotent; no-op if never added).
    if (listenerInstalled) {
      try { chrome.downloads.onCreated.removeListener(onCreatedListener); }
      catch (rmErr) { diag(result, `(listener cleanup ignored: ${String(rmErr)})`); }
    }
  }

  return result;
}
```

**Use for:** Plan 03-02 if event-log triggers (page.click / page.type / dispatchEvent) require pre-SAVE setup beyond what RESEARCH §"Code Examples" pattern 2 describes; Plan 03-03 password-sentinel typing pre-SAVE.

**Page-side extended-result shape (when host needs page data beyond AssertionResult)** — `A25Result` lines 2997-3002 + `A27Result` lines 3145-3148:

```typescript
interface A25Result extends AssertionResult {
  t0: number;        // performance.now() at SAVE dispatch
  tAck: number;      // performance.now() at SAVE ack
  t0Wall: number;    // Date.now() at SAVE dispatch (cross-realm bracket anchor)
  ackSuccess: boolean;
}

interface A27Result extends AssertionResult {
  tabAUrl: string;
  tabBUrl: string;
}
```

**Use for:** Plan 03-04 OPTIONAL Page.metrics scaffolding — `A3XResult extends AssertionResult { jsHeapUsedBytes: number; jsHeapTotalBytes: number; }` if Plan 03-04 ships scaffolding (D-P3-04 "if practical"; see RESEARCH §"Code Example A3X").

**`__mokoshHarness` registration pattern** — lines 3332-3372 (TypeScript ambient interface) + lines 3374-3404 (object literal):

```typescript
declare global {
  interface Window {
    __mokoshHarness: {
      assertA1: () => Promise<AssertionResult>;
      // ... (24 baseline assertions A1..A23)
      assertA24: () => Promise<AssertionResult>;
      assertA25: () => Promise<A25Result>;
      assertA26: () => Promise<AssertionResult>;
      assertA27: () => Promise<A27Result>;
      assertA28: () => Promise<AssertionResult>;
      getManifestVersion: () => Promise<string>;
    };
  }
}

window.__mokoshHarness = {
  assertA1, assertA2, /* ... */ assertA27, assertA28, getManifestVersion,
};
```

**Use for:** Plans 03-01..04 each append their own `assertA<NN>` to BOTH the `declare global` interface AND the `window.__mokoshHarness = {...}` object literal. Lockstep is critical; missing one side breaks the orchestrator's `await harness.assertA<NN>()` call.

---

### `tests/uat/lib/harness-page-driver.ts` (host-side `driveA29..A3X` + `JSZip`)

**Analog:** `tests/uat/lib/harness-page-driver.ts:1202-1849` (Plan 02-04 driveA24-A28)

**Existing imports (already present in file)** — lines 36-45:

```typescript
import { spawnSync } from 'node:child_process';
import { existsSync, mkdtempSync, readFileSync, readdirSync, statSync, unlinkSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join, resolve as resolvePath } from 'node:path';

import JSZip from 'jszip';
import type { Page } from 'puppeteer';

import type { AssertionRecord, CheckRecord } from './assertions';
import { assertArchiveShape, extractEntryToFile } from './zip';
```

Plan 03-01 only needs to ADD a single import for the rrweb EventType enum:
```typescript
import { EventType } from '@rrweb/types';   // ← NEW for Plan 03-01 (verified at node_modules/@rrweb/types/dist/index.d.ts:186-194)
```

Plan 03-02 / 03-03 may add an import for `UserEvent` from `src/shared/types.ts`:
```typescript
import type { UserEvent } from '../../../src/shared/types';   // ← NEW for Plan 03-02 events.json grep
```

**Standard `page.evaluate` wrapper for page-orchestrated assertions** — driveA24 lines 1202-1209:

```typescript
export async function driveA24(page: Page): Promise<AssertionRecord> {
  return await page.evaluate(async () => {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any -- evaluate runs in browser context where Window types are loose.
    const harness = (window as any).__mokoshHarness;
    const r: AssertionRecord = await harness.assertA24();
    return r;
  }) as AssertionRecord;
}
```

**Use for:** Plan 03-02 driveA30 (if Plan 03-02 chooses page-side orchestration for event triggers — but RESEARCH recommends Puppeteer-side `page.click` / `page.type` via the page, not chrome.runtime.sendMessage round-trip; planner picks).

**Two-phase pattern (page-side stub + host-side JSZip read)** — driveA26 lines 1421-1567 (canonical 6-check meta.json shape gate; chains off A25):

```typescript
export async function driveA26(
  page: Page,
  downloadsDir: string,
): Promise<AssertionRecord> {
  // Phase 1 — page-side stub (uniform orchestrator shape).
  const pageResult = await page.evaluate(async () => {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any -- evaluate runs in browser context where Window types are loose.
    const harness = (window as any).__mokoshHarness;
    const r: AssertionRecord = await harness.assertA26();
    return r;
  }) as AssertionRecord;

  const mergedChecks: CheckRecord[] = pageResult.checks.slice();
  const mergedDiagnostics: string[] = pageResult.diagnostics.slice();

  // Phase 2 — locate A25's zip.
  const zipPath = findLatestZip(downloadsDir);
  if (zipPath === null) {
    mergedChecks.push({
      name: 'A26.0: at least one zip present in downloadsDir (chain-off A25)',
      expected: '>=1 zip',
      actual: 'no zip in downloadsDir',
      passed: false,
    });
    return { passed: false, name: pageResult.name, checks: mergedChecks,
             diagnostics: mergedDiagnostics, error: pageResult.error };
  }
  mergedDiagnostics.push(`A26 zipPath=${zipPath}`);

  // Phase 3 — load + inspect target file inside zip.
  const zipBytes = readFileSync(zipPath);
  const zip = await JSZip.loadAsync(zipBytes);
  const metaFile = zip.file('meta.json');
  // ... A26.1..A26.6 structural checks
  const mergedPassed = mergedChecks.every((c) => c.passed);
  return { passed: mergedPassed, name: pageResult.name, checks: mergedChecks,
           diagnostics: mergedDiagnostics, error: pageResult.error };
}
```

**Use for:** All four Plans 03-01..04 — same 3-phase shape. Plan 03-01 reads `rrweb/session.json`, Plan 03-02 reads `logs/events.json`, Plan 03-03 reads `logs/events.json` for sentinel grep.

**`findLatestZip` chain-off helper** — lines 1395-1406 (must be present; if Plan 03-* runs in a fresh wave the helper is already shipped by Plan 02-04):

```typescript
function findLatestZip(downloadsDir: string): string | null {
  const candidates = readdirSync(downloadsDir).filter(isZipFilename);
  if (candidates.length === 0) {
    return null;
  }
  const withMtimes = candidates.map((name) => ({
    name,
    mtimeMs: statSync(resolvePath(downloadsDir, name)).mtimeMs,
  }));
  withMtimes.sort((a, b) => b.mtimeMs - a.mtimeMs);
  return resolvePath(downloadsDir, withMtimes[0].name);
}
```

**Use for:** Every Plan 03-01..04 driver that reads from downloadsDir. Already present in file (no re-implementation).

**EventType enum grep pattern (Plan 03-01)** — derived from RESEARCH §"Code Examples A29" (verified against `@rrweb/types/dist/index.d.ts:186-194`):

```typescript
// Plan 03-01 driveA29 — structural rrweb event-shape grep (RESEARCH-cited pattern; no codebase analog)
import { EventType } from '@rrweb/types';   // FullSnapshot=2, IncrementalSnapshot=3, Meta=4

const rrwebRaw = await zip.file('rrweb/session.json')!.async('text');
const events: Array<{ type: number; timestamp: number }> = JSON.parse(rrwebRaw);

mergedChecks.push({
  name: 'A29.1: rrweb/session.json contains > 0 events',
  expected: '>0',
  actual: events.length,
  passed: events.length > 0,
});
mergedChecks.push({
  name: `A29.2: rrweb emitted at least one Meta event (EventType.Meta=${EventType.Meta})`,
  expected: 'has Meta',
  actual: events.some((e) => e.type === EventType.Meta),
  passed: events.some((e) => e.type === EventType.Meta),
});
mergedChecks.push({
  name: `A29.3: rrweb emitted at least one FullSnapshot (EventType.FullSnapshot=${EventType.FullSnapshot})`,
  expected: 'has FullSnapshot',
  actual: events.some((e) => e.type === EventType.FullSnapshot),
  passed: events.some((e) => e.type === EventType.FullSnapshot),
});
mergedChecks.push({
  name: `A29.4: rrweb emitted at least one IncrementalSnapshot (EventType.IncrementalSnapshot=${EventType.IncrementalSnapshot})`,
  expected: 'has IncrementalSnapshot',
  actual: events.some((e) => e.type === EventType.IncrementalSnapshot),
  passed: events.some((e) => e.type === EventType.IncrementalSnapshot),
});
```

**Use for:** Plan 03-01 only. RESEARCH §"Pitfall 1" warns: synthetic probe HTML needs at least one DOM mutation between load and SAVE for `IncrementalSnapshot` to fire — Plan 03-01 driver MUST trigger one via `page.evaluate(() => document.body.appendChild(...))` or `page.click('#probe-modal-trigger')`.

**UserEvent type-grep pattern (Plan 03-02)** — derived from RESEARCH §"Code Examples" pattern 2 + `src/shared/types.ts:124-131`:

```typescript
// Plan 03-02 driveA30 — events.json grep for 5 UserEvent.type values
import type { UserEvent } from '../../../src/shared/types';

const eventsRaw = await zip.file('logs/events.json')!.async('text');
const userEvents: UserEvent[] = JSON.parse(eventsRaw);

const EXPECTED_TYPES = ['click', 'input', 'navigation', 'js_error', 'network_error'] as const;
for (const expectedType of EXPECTED_TYPES) {
  mergedChecks.push({
    name: `A30.<i>: logs/events.json contains at least one '${expectedType}' event`,
    expected: `>=1 ${expectedType}`,
    actual: userEvents.filter((e) => e.type === expectedType).length,
    passed: userEvents.some((e) => e.type === expectedType),
  });
}
```

**Negative-assertion pattern (Plan 03-03 password sentinel grep)** — derived from RESEARCH §"Pattern 3" (no codebase analog; closest analog is driveA27's A27.7/A27.8 absence assertions at harness-page-driver.ts:1724-1737):

```typescript
// Plan 03-03 driveA31 — sentinel absence from logs/events.json
const SENTINEL = 'secret-do-not-log-123';   // fixed; not a real secret
const eventsRaw = await zip.file('logs/events.json')!.async('text');
const userEvents: UserEvent[] = JSON.parse(eventsRaw);

const eventsContainingSentinel = userEvents.filter(
  (e) => e.value !== undefined && e.value.includes(SENTINEL),
);
mergedChecks.push({
  name: 'A31.1: password sentinel ABSENT from logs/events.json (existing src/content/index.ts:82 filter VERIFIED)',
  expected: 'absent (0 events containing sentinel)',
  actual: `${eventsContainingSentinel.length} events containing sentinel`,
  passed: eventsContainingSentinel.length === 0,
});
```

**Filter-pipeline form (no `continue`)** — driveA28 lines 1808-1810 (project style; CLAUDE.md "Control Flow" §):

```typescript
const actualPaths: string[] = Object.keys(zip.files)
  .filter((path) => !zip.files[path].dir)
  .sort();
```

**Use for:** Any enumeration loop in Plans 03-01..04. No `for...of` + `if (...) continue;` shape.

**Tab-cleanup safety pattern (T-02-04-04)** — assertA27 lines 3271-3289 (try/catch silent-ignore on already-closed):

```typescript
} finally {
  // T-02-04-04 mitigation: cleanup tabs with silent-ignore on already-closed.
  if (tabAId !== undefined) {
    try { await chrome.tabs.remove(tabAId); }
    catch (rmErr) { diag(result, `(tabA cleanup ignored: ${String(rmErr)})`); }
  }
  if (tabBId !== undefined) {
    try { await chrome.tabs.remove(tabBId); }
    catch (rmErr) { diag(result, `(tabB cleanup ignored: ${String(rmErr)})`); }
  }
}
```

**Use for:** Plan 03-02 if event-log trigger strategy involves opening a probe tab (e.g., `https://example.com` for js_error/network_error triggers).

---

### `tests/uat/harness.test.ts` (orchestrator wiring)

**Analog:** `tests/uat/harness.test.ts:65-130 + 316-335 + 406-430` (Plan 02-04)

**Import section pattern** — lines 92-100 (add A24-A28 imports per plan):

```typescript
  // Plan 02-04 Task 1 — D-P2-01 empirical Blob URL verification
  driveA24,
  // Plan 02-04 Task 2 — REQ-archive-export-latency (5s ceiling)
  driveA25,
  // Plan 02-04 Task 3 — meta.json 8-field + multi-tab strict + REQ-archive-layout
  driveA26,
  driveA27,
  driveA28,
  getManifestVersion,
} from './lib/harness-page-driver';
```

**Use for:** Each Plan 03-01..04 appends ONE `driveA<NN>` import + a section banner comment naming the plan and assertion purpose.

**Wrapped-driver pattern (when driver needs `downloadsDir` beyond the standard `Page` arg)** — lines 322-335 (Plan 02-04 wrappers):

```typescript
  // Plan 02-04 Task 2 — driveA25 needs downloadsDir for the host-side
  // dispatch→file-on-disk latency check (mirrors A5/A12/A13 wrapping).
  const driveA25Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
    (page) => driveA25(page, handles.downloadsDir);
  // Plan 02-04 Task 3 — driveA26/A27/A28 need downloadsDir for host-side
  // zip inspection (JSZip-parse meta.json + zip-layout enumeration). A26
  // chains off A25's zip (no new SAVE); A27 owns its SAVE (multi-tab);
  // A28 chains off A27's zip (no new SAVE).
  const driveA26Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
    (page) => driveA26(page, handles.downloadsDir);
  const driveA27Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
    (page) => driveA27(page, handles.downloadsDir);
  const driveA28Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
    (page) => driveA28(page, handles.downloadsDir);
```

**Use for:** Plans 03-01..03 (all need `downloadsDir` to find the latest zip). Same wrapping pattern; one wrapper per driver.

**Drivers-array push pattern with explanatory banner comment** — lines 397-430 (Plan 02-04):

```typescript
    // Plan 02-04 Task 1 A24: D-P2-01 empirical Blob URL verification.
    // Installs chrome.downloads.onCreated listener cross-realm, dispatches
    // SAVE_ARCHIVE, captures the download URL, asserts the `blob:` prefix
    // (closes audit P0-6 end-to-end through a real Chrome instance +
    // the offscreen mint round-trip + chrome.downloads platform call).
    { name: 'A24', drive: driveA24 },
    // Plan 02-04 Task 2 A25: REQ-archive-export-latency / SPEC §10 #6.
    { name: 'A25', drive: driveA25Wrapped },
    // Plan 02-04 Task 3 A26: D-P2-02 + D-P2-03 meta.json 8-field shape.
    { name: 'A26', drive: driveA26Wrapped },
    // Plan 02-04 Task 3 A27: STRICT multi-tab urls[] post DEC-011 Amendment 1.
    { name: 'A27', drive: driveA27Wrapped },
    // Plan 02-04 Task 3 A28: REQ-archive-layout strict 5-entry zip-layout.
    { name: 'A28', drive: driveA28Wrapped },
  ];
```

**Use for:** Plans 03-01..04 each append ONE `{ name: 'A<NN>', drive: driveA<NN>Wrapped }` entry with a banner comment citing the plan, the SPEC §10 # being verified, and the chaining strategy (own SAVE vs chain off prior).

**FORBIDDEN_HOOK_STRINGS UAT A0 mirror** — lines 115-130 (12 entries):

```typescript
const FORBIDDEN_HOOK_STRINGS: ReadonlyArray<string> = [
  '__mokoshTest',
  'setCurrentStream',
  'setSegmentCountGetter',
  'installFakeDisplayMedia',
  'uninstallFakeDisplayMedia',
  'dispatchEndedOnTrack',
  'getSegmentCount',
  '__mokoshOffscreenQuery',
  'get-display-surface',
  'get-segment-count',
  // Plan 01-14 A23 surface — lockstep with unit-gate inventory at
  // tests/background/no-test-hooks-in-prod-bundle.test.ts:105.
  'lastGetDisplayMediaConstraints',
  'get-last-getDisplayMedia-constraints',
];
```

**Lockstep requirement:** ANY new test-only `__MOKOSH_UAT__`-gated symbol introduced by Plan 03-* MUST be added to BOTH this UAT A0 mirror AND the unit-gate at `tests/background/no-test-hooks-in-prod-bundle.test.ts:108-126`. RESEARCH §"Anti-Patterns" + A6 in Assumptions Log: Phase 3 plans are EXPECTED to stay at 12 entries (rrweb + chrome.downloads + chrome.tabs are production surfaces). The MEDIUM-risk exception (A6) is Plan 03-04 Page.metrics scaffolding — Page.metrics is host-side (not bundled into page-realm); no new symbol expected.

---

### `tests/uat/extension-page-harness.html` (probe HTML append for Plan 03-01)

**Analog:** Current state of the file (lines 17-22) — append below, do NOT touch the head.

**Existing scaffold** (full file, 24 lines):

```html
<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Mokosh UAT Harness (extension-internal page)</title>
    <!--
      Plan 01-12 Wave 6: load the canonical token system on the harness
      page so A18 (Lora WOFF2 reachable via @font-face) and A21
      (--mks-font-display resolves to Lora) both have the @font-face
      rules + CSS custom properties + .mks-display-1 class visible via
      document.styleSheets + getComputedStyle. Vite's crxjs plugin
      handles the asset path rebasing at build:test time so the link
      resolves under dist-test/ even with content-hashed asset filenames.
    -->
    <link rel="stylesheet" href="../../src/shared/tokens.css">
  </head>
  <body>
    <h1>Mokosh UAT — extension-internal page harness</h1>
    <p>This page lives at <code>chrome-extension://&lt;id&gt;/tests/uat/extension-page-harness.html</code>.</p>
    <p>Puppeteer navigates a tab here and drives assertions via <code>window.__mokoshHarness.*</code>.</p>
    <pre id="status">Ready.</pre>
    <script type="module" src="./extension-page-harness.ts"></script>
  </body>
</html>
```

**Probe-HTML append target:** between `<pre id="status">` (line 21) and `<script type="module">` (line 22). Form + table + modal-trigger HTML per RESEARCH §"Pitfall 4" (NO `<textarea>`; rrweb alpha.4 bug #1596).

**Critical constraints (per RESEARCH Assumption A2 + A5):**
- DO NOT modify the `<head>` block — `<link rel="stylesheet" href="../../src/shared/tokens.css">` is load-bearing for A18 + A21.
- DO NOT add stylesheet imports for the probe HTML — inline styles via `style="..."` or via the existing tokens.css `--mks-*` vars (defensive).
- Probe HTML stays minimal: 1 form (`<input type="text">` + `<input type="email">` + `<input type="password">` + `<button>`), 1 small table (2-3 rows), 1 hidden modal `<div>` toggled by a trigger button. Per RESEARCH §"Pitfall 1": at least one DOM mutation is required pre-SAVE for `IncrementalSnapshot` to fire.

---

### `.planning/phases/03-.../03-VERIFICATION.md` (NEW; aggregator)

**Analogs:**
- `.planning/phases/02-stabilize-export-pipeline/02-VERIFICATION.md` (T5 override pattern + `overrides_applied` field; closest match for Plan 03-05 charter)
- `.planning/phases/01-stabilize-video-pipeline/01-VERIFICATION.md` (per-requirement scorecard + cross-cutting gates + operator empirical acks + deferred items)

**Frontmatter shape (from `02-VERIFICATION.md:1-32`):**

```yaml
---
phase: 02-stabilize-export-pipeline
verified: 2026-05-20T18:00:00Z
status: passed
score: 5/5 must-haves verified
overrides_applied: 1
override_notes:
  - dimension: "T5 operator empirical UAT (Plan 02-04 Task 4 Step 2)"
    initial_status: "UNCERTAIN (human_needed)"
    override_to: "VERIFIED"
    rationale: |
      User explicit delegation 2026-05-20: "why do i need to do all of this? It's on you to test..."
      established the operating principle that automation covers what automation can cover.
      Per saved memory feedback-trust-harness-over-manual-uat.md (created same session 2026-05-20),
      operator empirical UAT is reserved for surfaces automation genuinely cannot verify (brand
      judgment, ergonomics). For Phase 2 deep-pipeline work (Blob URL, meta schema, archive layout),
      every operator-checklist surface IS covered by harness assertions:
        - (a) <5s latency → A25 empirical via Puppeteer (real Chrome)
        - ... (5 sub-bullets covering each empirical channel)
      ... (citation block ending with "The harness IS the canonical Phase 2 verification per the current memory.")
human_verification: []
---
```

**Phase 3 adaptation (per CONTEXT D-P3-02 + D-P3-04):**

```yaml
---
phase: 03-spec-10-smoke-verification-dom-event-log-verification
verified: 2026-05-20T<HH-MM-SS>Z
status: passed
score: 9/9 SPEC §10 criteria
overrides_applied: 1
override_notes:
  - dimension: "SPEC §10 #8 — Password masking (PARTIAL per D-P3-02 charter)"
    initial_status: "PARTIAL"
    rationale: |
      Full rrweb v2 maskInputFn + data-sensitive guards DEFERRED per 2026-05-20 charter
      'we don't care about privacy hardening. At least here.' REQ-password-confidentiality
      moved to Out of Scope v1. Existing src/content/index.ts:82
      `if (target.type === 'password') return;` filter VERIFIED by Plan 03-03 A31
      (sentinel string typed; greps events.json for absence).
human_verification:
  - dimension: "SPEC §10 #9 — Extension RAM ≤ 50 MB"
    rationale: |
      Per D-P3-04: operator instructions in VERIFICATION below — load extension, idle 5 min,
      open chrome://memory-internals OR chrome://extensions service-worker memory display,
      verify extension background RAM < 50 MB. Page.metrics scaffolding (if shipped by
      Plan 03-04) measures page-realm only and does not cover the SW target.
---
```

**Per-Requirement Scorecard table** (from `01-VERIFICATION.md:32-46`):

```markdown
## Per-Requirement Scorecard

| # | Requirement / Decision | Evidence | Status |
|---|---|---|---|
| 1 | REQ-video-ring-buffer | `src/offscreen/recorder.ts:52-58` (`MAX_SEGMENTS=3 × 10s = 30s`); ... | PASS |
| 2 | REQ-install-clean | `npm run build` exit 0, 9 chunks produced ... | PASS |
| ... |
```

**Phase 3 adaptation:** §10 #1-#9 row-by-row evidence table with Phase-citation (Phase 1 / Phase 2 / Phase 3) + plan-citation (e.g., "Plan 03-01 A29 GREEN") + commit-citation per criterion.

**Cross-Cutting Gates table** (from `01-VERIFICATION.md:48-56`):

```markdown
## Cross-Cutting Gates

| Gate | Evidence | Status |
|---|---|---|
| vitest | 28 files / **153 tests / 153 GREEN** ... | PASS |
| UAT harness | 24 drivers (A0 grep gate + A1..A14 + A15..A17 + A18..A22 + A23) ... | PASS |
| Tier-1 grep gate | 12 FORBIDDEN_HOOK_STRINGS ... | PASS |
| Pre-checkpoint bundle gates | 0 `googleapis`/`https://fonts` in dist; 0 test-hook leaks ... | PASS |
| tsc | `npx tsc --noEmit` exit 0 | PASS |
```

**Phase 3 adaptation:** Update UAT harness row (3X drivers post Plan 03-01..04); preserve baseline vitest + Tier-1 + bundle gates; cite Plan 03-05's own re-verification of all 6 pre-checkpoint bundle gates per saved memory `feedback-pre-checkpoint-bundle-gates.md`.

**Operator-Empirical Acks table** (from `01-VERIFICATION.md:70-78`):

```markdown
## Operator-Empirical Acks (verbatim + commit refs)

| Date | Plan | Operator response | Commit |
|---|---|---|---|
| 2026-05-15 | 01-07 (D-12 + A3 closure) | Chrome playback clean, ffmpeg dry-run exit 0 | cd61cbc |
| ... |
```

**Phase 3 adaptation:** Single row for the §10 #9 RAM operator ack (when received). Empty until ack lands; then verbatim quote + commit.

**Deferred Items section** (from `01-VERIFICATION.md:92-104` + `02-VERIFICATION.md:55-58`):

```markdown
## Forward-Looking Deferred Items (NOT gaps)

| Item | Owner | Source |
|---|---|---|
| rrweb v2 stable upgrade | Phase 4 | D-P3-03 defer rationale |
| Programmatic RAM measurement (puppeteer.Page.metrics enhancement OR chrome.devtools Memory API) | Phase 4 | D-P3-04 defer rationale |
| REQ-password-confidentiality v2 candidate (rrweb v2 maskInputFn + data-sensitive guards) | Phase 4 | D-P3-02 defer rationale |
| ... |
```

**Phase 3 adaptation:** Pull from CONTEXT §"Deferred" verbatim (10 items including the audit P1 polish + setimmediate polyfill + ROADMAP backfill).

---

### `tests/uat/lib/ramMetrics.ts` (OPTIONAL — Plan 03-04 Page.metrics scaffolding)

**Analog:** NONE in codebase. Closest scaffolding shape: `driveA25` host-side latency measurement pattern (`tests/uat/lib/harness-page-driver.ts:1255-1334`). New pattern; cite RESEARCH §"Code Example A3X" + §"Pitfall 2".

**Decision per D-P3-04 + RESEARCH Open Question 3 (recommended: SHIP):** Plan 03-04 ships ~30 lines of Page.metrics scaffolding either inline in `harness-page-driver.ts` (preferred per scope-minimization) OR as a new `tests/uat/lib/ramMetrics.ts` helper if planner prefers separation. RESEARCH §"Open Question 3" recommends shipping with explicit diagnostic copy.

**Concrete pattern (per RESEARCH §"Code Example A3X"):**

```typescript
// Plan 03-04 optional driveA3X — Page.metrics() scaffolding (D-P3-04 best-effort)
async function driveA3X_OptionalRamScaffold(page: Page): Promise<AssertionRecord> {
  // Page.metrics is page-realm only — JSHeapUsedSize covers V8 isolate of THIS Page,
  // NOT the MV3 service worker (separate target).
  const metrics = await page.metrics();
  const jsHeapMB = metrics.JSHeapUsedSize !== undefined
    ? metrics.JSHeapUsedSize / (1024 * 1024)
    : -1;

  const checks: CheckRecord[] = [
    {
      name: 'A3X.1: Page.metrics returned JSHeapUsedSize',
      expected: '>= 0',
      actual: String(jsHeapMB),
      passed: jsHeapMB >= 0,
    },
    {
      name: 'A3X.2: Page-realm JS heap < 50 MB (NOTE: scaffolding only; SW context excluded)',
      expected: '< 50 MB',
      actual: `${jsHeapMB.toFixed(2)} MB`,
      passed: jsHeapMB < 50,
    },
  ];

  return {
    passed: checks.every((c) => c.passed),
    name: 'A3X — RAM scaffolding (best-effort; page-realm only per D-P3-04)',
    checks,
    diagnostics: [
      'NOTE: page-realm only; SW context measurement requires chrome://memory-internals operator verification per D-P3-04.',
    ],
  };
}
```

**Critical diagnostic copy gate (per RESEARCH §"Pitfall 2"):** The scaffolding MUST emit `'NOTE: page-realm only; SW context excluded'` in diagnostics so an operator does not interpret a green automation number as full §10 #9 closure. The binding §10 #9 gate is the operator chrome://memory-internals check; scaffolding is informational only.

---

## Shared Patterns

### Approach B Harness Extension Lockstep

**Source:** Plan 02-04 + Plan 01-13 (Approach B foundation)
**Apply to:** Plans 03-01, 03-02, 03-03, 03-04 (every Phase 3 plan that ships a new assertion)

The 3-file lockstep across each new assertion:

1. **`tests/uat/extension-page-harness.ts`** — append `async function assertA<NN>(): Promise<AssertionResult>` (page-side stub OR orchestrator) + extend `declare global` interface + add entry to `window.__mokoshHarness = {...}` object literal.
2. **`tests/uat/lib/harness-page-driver.ts`** — append `export async function driveA<NN>(page: Page, downloadsDir: string): Promise<AssertionRecord>` (3-phase pattern: page.evaluate stub → findLatestZip → JSZip read).
3. **`tests/uat/harness.test.ts`** — append `driveA<NN>` import + wrapped-driver const (if `downloadsDir` is needed) + drivers-array push with banner comment.

Missing ANY one of the three breaks the orchestrator (either at the `harness.assertA<NN>()` page.evaluate call OR at the `for (const drive of drivers)` loop). Plan-checker MUST validate all three are touched per new A-number.

### Pre-Checkpoint Bundle Gates (6/6 Standard Inventory)

**Source:** Saved memory `feedback-pre-checkpoint-bundle-gates.md` + `02-04-SUMMARY.md:158-168` (canonical 7-gate table; Phase 2 closure precedent)
**Apply to:** Plan 03-05 (before VERIFICATION.md is written) — ALL plans before any operator step

Standard 6/6 inventory (Plan 02-04 ran 7; Plan 03-05 should run the same):

| Gate | Concrete Check |
|------|----------------|
| Gate 1 | `npm run build` exit 0 |
| Gate 2 | SW CSP-safety: `grep -rn "new Function\\|eval(" dist/assets/` — 1 documented exception (setimmediate polyfill) |
| Gate 3 | SW Node-globals: `grep -rn "Buffer.from\\|Buffer.alloc\\|require(" dist/assets/index.ts-*.js` — 0 hits |
| Gate 4 | DOM-globals: `grep -rn "window.\\|document." dist/assets/index.ts-*.js` — bundled-lib idiom (typeof-guarded) |
| Gate 5 | Tier-1 SW-bundle-import gate (`tests/background/sw-bundle-import.test.ts`) GREEN |
| Gate 6 | FORBIDDEN_HOOK_STRINGS unit gate (`tests/background/no-test-hooks-in-prod-bundle.test.ts`) — 12 strings, 0 hits each |
| Gate 7 | Manifest validation gates: i18n + locale-parity + build — all GREEN |

### T5 Override Pattern (Harness-Coverage-as-Verification)

**Source:** `02-VERIFICATION.md:1-31` + saved memory `feedback-trust-harness-over-manual-uat.md`
**Apply to:** Plan 03-05 VERIFICATION.md — for §10 criteria where harness coverage exists (§10 #4 / #5 / #8) but NOT for §10 #9 RAM (genuine non-automatable)

When verifier returns `human_needed` for a criterion AND a harness assertion empirically covers the same surface:
- Move `human_verification` entry to `overrides_applied` block in frontmatter
- Include explicit user-delegation citation (date + verbatim quote, if recorded) + saved-memory reference
- Sub-bullet each harness assertion that covers the surface
- Mark `status: passed` rather than `status: human_needed`

**Counter-example (do NOT override):** §10 #9 RAM measurement — Page.metrics scaffolding is page-realm only (RESEARCH §"Pitfall 2"); the SW context can ONLY be measured via operator-driven chrome://memory-internals. This is the canonical `human_verification` entry per D-P3-04.

### Filter-Pipeline Form (No `continue`)

**Source:** `~/.claude/CLAUDE.md` "Control Flow" § + Plan 02-04 driveA28 (lines 1808-1810)
**Apply to:** Any enumeration loop in Plans 03-01..04

```typescript
// PREFERRED — filter pipeline
const matchingEvents = userEvents.filter((e) => e.type === 'click');
const realHttpUrls = urls.filter((u) => /^https?:\/\//.test(u));

// AVOID — for...of + continue
// for (const e of userEvents) { if (e.type !== 'click') continue; ... }
```

### Production-Surface-Only New Assertions (FORBIDDEN_HOOK_STRINGS stays at 12)

**Source:** `02-04-SUMMARY.md:99` + RESEARCH Assumption A6
**Apply to:** Plans 03-01..04 — riding production surfaces (rrweb.record + content-script GET_RRWEB_EVENTS + chrome.tabs.create + chrome.downloads.onCreated)

Phase 3 assertions ride production surfaces verified by Plans 01-13 + 02-04. NO new `__MOKOSH_UAT__`-gated test-only symbols expected. If Plan 03-04 Page.metrics scaffolding requires a new bridge op (e.g., `get-page-metrics` from offscreen → harness), that scenario adds 1-2 entries to BOTH FORBIDDEN_HOOK_STRINGS inventories AND requires Vite define-token tree-shake gating. Plan-checker MUST validate inventory count.

### Anti-Pattern: Re-reading the Same Range

**Source:** CLAUDE.md operator guidance
**Apply to:** All Phase 3 implementation work — read each source file ONCE, extract patterns, then implement

---

## No Analog Found

| File | Role | Data Flow | Reason / Mitigation |
|------|------|-----------|---------------------|
| `tests/uat/lib/ramMetrics.ts` (if Plan 03-04 chooses separate-file scaffolding) | test (host-side utility) | request-response (CDP Performance.getMetrics) | Page.metrics() has no codebase precedent. RESEARCH §"Code Example A3X" provides the canonical implementation; planner uses verbatim. Plan 03-04 may inline this in `harness-page-driver.ts` instead of new file (scope-minimization preferred). |

All other anticipated files have direct analogs from Plan 02-04 (most recent Approach B precedent).

## Per-Plan Anticipated File Touch Inventory

| Plan | Files Modified | Files Created | Pattern Source |
|------|----------------|---------------|----------------|
| 03-01 (rrweb DOM §10 #4) | `tests/uat/extension-page-harness.ts` + `tests/uat/extension-page-harness.html` (probe HTML) + `tests/uat/lib/harness-page-driver.ts` + `tests/uat/harness.test.ts` | — | Plan 02-04 (assertA26/driveA26 + JSZip + EventType import) |
| 03-02 (event-log §10 #5) | `tests/uat/extension-page-harness.ts` + `tests/uat/lib/harness-page-driver.ts` + `tests/uat/harness.test.ts` | — | Plan 02-04 (driveA26 chain pattern + UserEvent grep from src/shared/types.ts:124-131) |
| 03-03 (password-filter §10 #8 PARTIAL) | `tests/uat/extension-page-harness.ts` + `tests/uat/lib/harness-page-driver.ts` + `tests/uat/harness.test.ts` (possibly probe HTML if Plan 03-01 didn't add `<input type="password">`) | — | RESEARCH §"Pattern 3" + driveA27 absence-assertion shape |
| 03-04 (RAM §10 #9 best-effort) | OPTIONAL: `tests/uat/lib/harness-page-driver.ts` (Page.metrics inline) + `tests/uat/harness.test.ts` (wrapped driver) | OPTIONAL: `tests/uat/lib/ramMetrics.ts` | RESEARCH §"Code Example A3X" (no codebase analog) |
| 03-05 (§10 sweep aggregator) | — | `.planning/phases/03-.../03-VERIFICATION.md` | `01-VERIFICATION.md` (scorecard structure) + `02-VERIFICATION.md` (T5 override frontmatter) |

## Wave Sequencing Note

Per CONTEXT §"Claude's Discretion" + RESEARCH Open Question 1 + Pitfall 6: Plans 03-01..04 modify the SAME three harness files (`extension-page-harness.ts`, `harness-page-driver.ts`, `harness.test.ts`). RESEARCH recommends SEQUENTIAL execution within Wave 2: 03-01 → 03-02 → 03-03 → 03-04. Plan-checker validates `files_modified` overlap audit. Plan 03-05 (VERIFICATION.md aggregator) runs in Wave 3 after 03-01..04 land + UAT harness reaches 33/33 (or 32/32 if Plan 03-04 skips scaffolding).

## Metadata

**Analog search scope:** `tests/uat/`, `.planning/phases/01-stabilize-video-pipeline/`, `.planning/phases/02-stabilize-export-pipeline/`, `src/content/index.ts`, `src/shared/types.ts`, `node_modules/@rrweb/types/dist/index.d.ts`

**Files read (each ONCE, non-overlapping ranges):**
- `tests/uat/extension-page-harness.ts:2840-3409` (assertA24-A28 + __mokoshHarness wire)
- `tests/uat/lib/harness-page-driver.ts:1-130, 1180-1349, 1360-1599, 1700-1849` (4 non-overlapping ranges; covers driveA24/A25/A26/A27/A28 + findLatestZip + A28_EXPECTED_PATHS + imports)
- `tests/uat/harness.test.ts:1-100, 100-260, 320-440` (3 non-overlapping ranges; covers orchestrator imports + FORBIDDEN_HOOK_STRINGS + A0 gate + drivers wrap + push)
- `tests/uat/extension-page-harness.html` (full; 24 lines)
- `tests/uat/lib/zip.ts` (full; 140 lines)
- `tests/background/no-test-hooks-in-prod-bundle.test.ts:95-175` (FORBIDDEN_HOOK_STRINGS unit-gate)
- `.planning/phases/01-stabilize-video-pipeline/01-VERIFICATION.md` (full; 123 lines)
- `.planning/phases/02-stabilize-export-pipeline/02-VERIFICATION.md` (full; 166 lines)
- `.planning/phases/02-stabilize-export-pipeline/02-04-SUMMARY.md` (full; 259 lines)
- `src/content/index.ts:75-89` (password filter at line 82) + grep for rrweb wiring anchors
- `src/shared/types.ts:120-155` (UserEvent + SessionMetadata)
- `node_modules/@rrweb/types/dist/index.d.ts:186-194` (EventType enum)

**Pattern extraction date:** 2026-05-20