---
phase: 03
slug: spec-10-smoke-verification-dom-event-log-verification
plan: 03
type: execute
wave: 3
depends_on:
  - 01
  - 02
files_modified:
  - tests/uat/extension-page-harness.ts
  - tests/uat/lib/harness-page-driver.ts
  - tests/uat/harness.test.ts
autonomous: true
requirements: []
tags:
  - uat-harness
  - a31
  - password-filter
  - spec-10-8-partial
  - approach-b
  - negative-assertion
  - charter-d-p3-02
user_setup: []
must_haves:
  truths:
    - "Typing a sentinel value into the probe-page password input does NOT cause that value to appear in logs/events.json (existing src/content/index.ts:82 filter fires)"
    - "Counts of UserEvent entries whose .value field contains the sentinel string = 0"
    - "Counts of UserEvent entries whose .target selector points at the password input = 0 (filter happens early-return BEFORE addUserEvent)"
    - "UAT harness exits 0 with 31 + 1 = 32/32 assertions GREEN (A30 baseline preserved + new A31)"
  artifacts:
    - path: "tests/uat/extension-page-harness.ts"
      provides: "assertA31 page-side orchestrator: types sentinel into #probe-password, runs setupFreshRecording + SAVE"
      contains: "assertA31"
    - path: "tests/uat/lib/harness-page-driver.ts"
      provides: "driveA31 host-side: JSZip-parse logs/events.json + negative-assertion sentinel grep"
      contains: "driveA31"
    - path: "tests/uat/harness.test.ts"
      provides: "driveA31 import + wrapped driver + drivers-array push entry"
      contains: "driveA31"
  key_links:
    - from: "tests/uat/lib/harness-page-driver.ts driveA31"
      to: "tests/uat/extension-page-harness.ts assertA31"
      via: "page.evaluate(() => window.__mokoshHarness.assertA31())"
      pattern: "harness.assertA31\\(\\)"
    - from: "tests/uat/extension-page-harness.ts assertA31"
      to: "src/content/index.ts:82 password filter (READ-ONLY VERIFICATION SUBJECT)"
      via: "synthetic password-input event triggers setupInputLogging filter early-return BEFORE addUserEvent"
      pattern: "if \\(target.type === 'password'\\)"
---

<objective>
Extend the UAT harness with A31 — empirical PARTIAL verification of SPEC
§10 #8. Per D-P3-02 locked decision: REQ-password-confidentiality is
Out of Scope v1; full rrweb v2 maskInputFn + data-sensitive guards are
deferred to Phase 4. Plan 03-03 confirms the EXISTING minimum filter at
`src/content/index.ts:82` (`if (target.type === 'password') return;`)
fires — sentinel string typed into the probe-page `<input type="password">`
MUST NOT appear in `logs/events.json`. This is a negative-assertion gate.

Purpose: Honors the charter literally — verify the existing
defense-in-depth without expanding scope; the PARTIAL mark in Plan
03-05 VERIFICATION.md will cite this A31 GREEN + the charter rationale.

Output: A31 assertion with 3 host-side checks (SAVE ack + sentinel
absent from events.json .value fields + zero events targeting the
password selector); UAT count 31 → 32 GREEN.
</objective>

<execution_context>
@$HOME/.claude/get-shit-done/workflows/execute-plan.md
@$HOME/.claude/get-shit-done/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/REQUIREMENTS.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-CONTEXT.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-RESEARCH.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-PATTERNS.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-01-PLAN.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-02-PLAN.md
@src/content/index.ts
@src/shared/types.ts

<interfaces>
<!-- Key contracts the executor needs. Extracted from existing code. -->

From src/content/index.ts (lines 77-96; READ-ONLY — verification subject):

  // setupInputLogging
  function setupInputLogging() {
    document.addEventListener('input', (event) => {
      const target = event.target as HTMLInputElement;

      // Пропускаем пароли  (line 81 comment; "skip passwords")
      if (target.type === 'password') {     // LINE 82 — the filter
        return;                              // LINE 83 — early-return BEFORE addUserEvent
      }

      const selector = getSelector(target);
      addUserEvent({                         // LINE 88 — never reached for password inputs
        timestamp: Date.now(),
        type: 'input',
        target: selector,
        value: target.value.substring(0, 200),
        url: window.location.href
      });
    }, true);
  }

From src/shared/types.ts (lines 124-131):

  export interface UserEvent {
    timestamp: number;
    type: 'click' | 'input' | 'navigation' | 'js_error' | 'network_error';
    target: string;     // CSS selector
    value?: string;     // What the user typed (up to 200 chars; omitted for passwords)
    url: string;
    meta?: Record<string, unknown>;
  }

From Plan 03-01: probe HTML in extension-page-harness.html provides
`<input type="password" id="probe-password" data-test="probe-password" />`.
The id-based selector means getSelector(target) returns `#probe-password`
for any logged event on this element (per src/content/index.ts:241-243).
</interfaces>

# Plan Anchors

- **Sequential wave assignment (per RESEARCH Pitfall 6 + file-overlap rule):** Plan 03-03 lives in wave 3
  modifies the SAME 3 harness files as Plans 03-01 + 03-02. depends_on:
  [01, 02] enforces sequential ordering.
- **Negative-assertion pattern (per RESEARCH Pattern 3 + Plan 02-04
  A27.7/A27.8 absence-check precedent):** The contract is
  `userEvents.filter(e => e.value contains SENTINEL).length === 0`.
  GREEN A31 = filter fired; RED A31 = filter regressed.
- **Sentinel is a fixed test constant, not a real secret:** Per RESEARCH
  Security Domain table, `secret-do-not-log-123` is a probe sentinel;
  logging it would itself trigger an explicit RED. No PII.
- **Targeting via id `#probe-password`:** the production getSelector at
  src/content/index.ts:240 returns `#${element.id}` when an id is
  present, so any event on the password input would have
  `target === '#probe-password'`. A31.3 asserts zero such entries.
- **Page-side approach with native dispatch:** set `.value` directly +
  dispatch `Event('input', { bubbles: true })` → fires production
  listener at line 78 → filter at line 82 early-returns.
- **Probe HTML reuse:** Plan 03-01 added the password input; Plan 03-03
  reuses it; no new HTML.
- **PARTIAL mark scope (D-P3-02 — NOT in scope):** rrweb v2 maskInputFn,
  data-sensitive guards, full §10 #8 closure deferred to Phase 4.
- **FORBIDDEN_HOOK_STRINGS lockstep:** A31 rides production listeners +
  existing helpers. Tier-1 inventory stays at 12 entries.
</context>

<tasks>

<task type="auto" tdd="false">
  <name>Task 1: Add assertA31 page-side orchestrator (sentinel-into-password trigger + SAVE)</name>
  <files>tests/uat/extension-page-harness.ts</files>
  <read_first>
    - tests/uat/extension-page-harness.ts where Plan 03-02 added assertA30 (study its shape; new assertA31 appends after it)
    - tests/uat/extension-page-harness.html (verify Plan 03-01 added the password input with id=probe-password)
    - src/content/index.ts lines 77-96 (the exact filter being verified)
  </read_first>
  <behavior>
    Adds module-local constants for A31 and the page-side assertA31
    function that:
    - Step 1: setupFreshRecording (clean event-log window)
    - Step 2: settle one segment
    - Step 3: set #probe-password.value to SENTINEL + dispatch input event (fires production listener; filter early-returns)
    - Step 4: settle synchronous handler completion
    - Step 5: dispatch SAVE_ARCHIVE
    - Push A31.1 (SAVE ack)
    - Registers assertA31 on declare global + __mokoshHarness object literal
    - Updates trailing console.log to mention Plan 03-03: A31
  </behavior>
  <action>
1. Open `tests/uat/extension-page-harness.ts`. Locate the assertA30 block added by Plan 03-02 and the `getManifestVersion` declaration following it.
2. Insert the new assertA31 block AFTER assertA30 (BEFORE getManifestVersion). Use this concrete code:

```typescript
/* ─── Plan 03-03 — A31 (password-filter PARTIAL; SPEC §10 #8) ────────
 *
 *   A31 — D-P3-02 PARTIAL: verify the existing minimum filter at
 *         src/content/index.ts:82 (`if (target.type === 'password') return;`)
 *         fires when the operator types into a password input.
 *         Negative-assertion contract: SENTINEL value MUST be absent
 *         from logs/events.json.
 *
 * Charter alignment (per CONTEXT.md D-P3-02 + REQUIREMENTS.md line 271):
 *   - REQ-password-confidentiality moved Out of Scope v1 per 2026-05-20
 *     charter "we don't care about privacy hardening. At least here."
 *   - Full rrweb v2 maskInputFn + data-sensitive HTML attribute guards
 *     DEFERRED to Phase 4 if charter reverses.
 *   - A31 verifies the EXISTING minimum (the line-82 filter) — does
 *     NOT expand scope.
 *
 * FORBIDDEN_HOOK_STRINGS impact: NONE. Tier-1 inventory stays at 12.
 */

/** SAVE_ARCHIVE dispatch timeout for A31 — matches A24/A25/A27/A29/A30. */
const A31_SAVE_ARCHIVE_TIMEOUT_MS = 15_000;
/** Pre-SAVE segment-settle window (10s rotation + 1s slack). */
const A31_SEGMENT_SETTLE_MS = 11_000;
/** Settle after sentinel-typing trigger so the synchronous handler completes. */
const A31_TRIGGER_SETTLE_MS = 500;
/** Fixed test sentinel — distinctive string the negative-assertion
 *  searches for in events.json. Per RESEARCH §"Security Domain":
 *  this is a probe sentinel, NOT a real secret; logging it would
 *  itself trigger an explicit RED. */
const A31_PASSWORD_SENTINEL = 'secret-do-not-log-123';
/** Production CSS selector returned by getSelector() at
 *  src/content/index.ts:241 for the password input (which has id).
 *  Drives A31.3 (target-absence check). */
const A31_PASSWORD_SELECTOR = '#probe-password';

/**
 * A31 — Password-filter PARTIAL empirical (SPEC §10 #8 PARTIAL per D-P3-02).
 *
 * Types the sentinel string into the probe-page password input then
 * SAVEs. Host-side driveA31 inspects logs/events.json and asserts
 * absence of (a) the sentinel value and (b) any entries targeting
 * the password selector.
 *
 * @returns AssertionResult with 1 page-side check (SAVE ack); host-side
 *          driveA31 appends 2 negative-assertion checks.
 */
async function assertA31(): Promise<AssertionResult> {
  const result: AssertionResult = {
    passed: false,
    name: 'A31 — password filter fires (SPEC §10 #8 PARTIAL per D-P3-02)',
    checks: [],
    diagnostics: [],
  };

  try {
    diag(result, 'Step 1: setupFreshRecording (A31 owns its recording — clean event-log window)');
    const setupResp = await setupFreshRecording();
    if (!setupResp.ok) {
      throw new Error(`setupFreshRecording failed: ${setupResp.error ?? '(no error)'}`);
    }
    diag(result, 'Step 1 OK — REC state established');

    diag(result, `Step 2: settle ${A31_SEGMENT_SETTLE_MS}ms for first segment rotation`);
    await new Promise((r) => setTimeout(r, A31_SEGMENT_SETTLE_MS));

    diag(result, `Step 3: type SENTINEL into ${A31_PASSWORD_SELECTOR} + dispatch input event`);
    const pwInput = document.querySelector<HTMLInputElement>(A31_PASSWORD_SELECTOR);
    if (pwInput === null) {
      throw new Error(`A31 trigger failed: ${A31_PASSWORD_SELECTOR} not found in DOM (probe HTML regression from Plan 03-01)`);
    }
    pwInput.value = A31_PASSWORD_SENTINEL;
    pwInput.dispatchEvent(new Event('input', { bubbles: true }));
    diag(result, 'Step 3 OK — sentinel typed; production filter at src/content/index.ts:82 should have early-returned');

    diag(result, `Step 4: settle ${A31_TRIGGER_SETTLE_MS}ms so synchronous handlers complete`);
    await new Promise((r) => setTimeout(r, A31_TRIGGER_SETTLE_MS));

    diag(result, 'Step 5: dispatch SAVE_ARCHIVE');
    const ack = await sendMessageWithTimeout<{ success: boolean; error?: string }>(
      { type: 'SAVE_ARCHIVE' },
      A31_SAVE_ARCHIVE_TIMEOUT_MS,
      'SAVE_ARCHIVE (A31)',
    );
    diag(result, `Step 5 result: ${JSON.stringify(ack)}`);

    result.checks.push({
      name: 'A31.1: SAVE_ARCHIVE ack received with success=true',
      expected: true,
      actual: ack.success,
      passed: ack.success === true,
    });

    result.passed = result.checks.every((c) => c.passed);
  } catch (err) {
    result.error = err instanceof Error ? err.message : String(err);
    diag(result, `THREW: ${result.error}`);
  }

  return result;
}
```

3. In the `declare global { interface Window { __mokoshHarness: { ... } } }` block, AFTER the assertA30 entry from Plan 03-02 and BEFORE `getManifestVersion`, insert:

```typescript
      // Plan 03-03 — password-filter PARTIAL (SPEC §10 #8 PARTIAL per D-P3-02)
      assertA31: () => Promise<AssertionResult>;
```

4. In the `window.__mokoshHarness = { ... }` object literal, AFTER `assertA30,` and BEFORE `getManifestVersion,` insert:

```typescript
  assertA31,
```

5. Update the closing `console.log(...)` line to append `+ Plan 03-03: A31`. Concrete replacement:

```typescript
console.log('[harness-page] ready — window.__mokoshHarness installed (Plan 01-13 Task 9: A1..A14 + Plan 01-10 Wave 3: A15..A17 + Plan 01-12 Wave 6: A18..A22 + Plan 01-14: A23 + Plan 02-04 Tasks 1-2: A24+A25 + Plan 02-04 Task 3: A26+A27+A28 + Plan 03-01: A29 + Plan 03-02: A30 + Plan 03-03: A31 + getManifestVersion)');
```

6. Run `npx tsc --noEmit`. Expected: clean.
  </action>
  <verify>
    <automated>npx tsc --noEmit; T=$(grep -c "assertA31" tests/uat/extension-page-harness.ts); test "$T" -ge 3 &amp;&amp; S=$(grep -c "A31_PASSWORD_SENTINEL" tests/uat/extension-page-harness.ts); test "$S" -ge 2 &amp;&amp; grep -q "'secret-do-not-log-123'" tests/uat/extension-page-harness.ts</automated>
  </verify>
  <acceptance_criteria>
    - `npx tsc --noEmit` exits 0.
    - `grep -c 'assertA31' tests/uat/extension-page-harness.ts` returns >=3 (function definition + declare global entry + object literal entry).
    - `grep -c 'A31_PASSWORD_SENTINEL' tests/uat/extension-page-harness.ts` returns >=2 (declaration + usage).
    - `grep -c \"'secret-do-not-log-123'\" tests/uat/extension-page-harness.ts` returns exactly 1.
    - Existing Plan 03-02 assertA30 entry still present.
  </acceptance_criteria>
  <done>
    Page-side assertA31 types sentinel into the password input + SAVEs; registered on __mokoshHarness; ready for Task 2 host-side driveA31 negative-assertion.
  </done>
</task>

<task type="auto" tdd="false">
  <name>Task 2: Add driveA31 host-side (sentinel-absence grep) + orchestrator wiring</name>
  <files>tests/uat/lib/harness-page-driver.ts, tests/uat/harness.test.ts</files>
  <read_first>
    - tests/uat/lib/harness-page-driver.ts where Plan 03-02 added driveA30 (same UserEvent import; same 3-phase shape)
    - tests/uat/harness.test.ts where Plan 03-02 added driveA30 wrapping + drivers entry
    - .planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-PATTERNS.md §"Negative-assertion pattern (Plan 03-03 password sentinel grep)"
  </read_first>
  <behavior>
    Host-side (`tests/uat/lib/harness-page-driver.ts`):
    - The `UserEvent` type import added by Plan 03-02 is reused (no new import needed).
    - Adds `export async function driveA31(page: Page, downloadsDir: string): Promise<AssertionRecord>`:
      - Phase 1 — page.evaluate harness.assertA31()
      - Phase 2 — findLatestZip; A31.0 if null
      - Phase 3 — JSZip.loadAsync; read logs/events.json; A31.0a if absent
      - Parse as UserEvent[]; A31.0b on JSON parse failure
      - Push check A31.2: events whose .value contains SENTINEL = 0
        (negative-assertion proves the filter fired)
      - Push check A31.3: events with target === '#probe-password' = 0
        (filter early-returns BEFORE addUserEvent)
      - Diagnostic includes count of total userEvents + count of events that match #probe-password selector + count of events whose value contains sentinel
      - Filter-pipeline form (no `continue`).

    Orchestrator (`tests/uat/harness.test.ts`):
    - Adds `driveA31,` to import block (after `driveA30,`).
    - Adds `driveA31Wrapped` const after driveA30Wrapped.
    - Adds `{ name: 'A31', drive: driveA31Wrapped },` to drivers array after the A30 entry.
    - Updates orchestrator banner to append `, A31`.
  </behavior>
  <action>
1. Open `tests/uat/lib/harness-page-driver.ts`. At the end of the file (AFTER driveA30 added by Plan 03-02), append:

```typescript

/* ─── Plan 03-03 — driveA31 (password-filter PARTIAL host-side) ─────── */

/** Fixed test sentinel — same value as page-side A31_PASSWORD_SENTINEL.
 *  Negative-assertion driver searches events.json for its absence. */
const A31_PASSWORD_SENTINEL = 'secret-do-not-log-123';
/** Selector the production getSelector returns for #probe-password. */
const A31_PASSWORD_SELECTOR = '#probe-password';

/**
 * Drive A31 (Plan 03-03 — SPEC §10 #8 PARTIAL per D-P3-02).
 *
 * Page-side assertA31 typed SENTINEL into the password input then
 * SAVEd. Host-side asserts that:
 *   - the sentinel string is ABSENT from any UserEvent.value field
 *     (proves the line-82 filter early-returned before addUserEvent)
 *   - no UserEvent has target === '#probe-password' (proves the same
 *     filter via the orthogonal selector path)
 *
 * Filter-pipeline form (no `continue`) per CLAUDE.md Control Flow §.
 *
 * Checks (3 total):
 *   - A31.1: SAVE_ARCHIVE ack (page-side)
 *   - A31.2: 0 events contain SENTINEL in .value field
 *   - A31.3: 0 events have target === '#probe-password'
 *
 * @param page         - The harness page from `launchHarnessBrowser`.
 * @param downloadsDir - Absolute path to the per-run downloads directory.
 * @returns AssertionRecord with 3 merged checks.
 */
export async function driveA31(
  page: Page,
  downloadsDir: string,
): Promise<AssertionRecord> {
  // Phase 1 — page-side orchestration + SAVE.
  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.assertA31();
    return r;
  }) as AssertionRecord;

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

  // Phase 2 — locate the produced zip.
  const zipPath = findLatestZip(downloadsDir);
  if (zipPath === null) {
    mergedChecks.push({
      name: 'A31.0: at least one zip present in downloadsDir',
      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(`A31 zipPath=${zipPath}`);

  // Phase 3 — load + inspect logs/events.json.
  const zipBytes = readFileSync(zipPath);
  const zip = await JSZip.loadAsync(zipBytes);
  const eventsFile = zip.file('logs/events.json');
  mergedChecks.push({
    name: 'A31.0a: logs/events.json entry exists in zip',
    expected: true,
    actual: eventsFile !== null,
    passed: eventsFile !== null,
  });

  if (eventsFile === null) {
    return {
      passed: false,
      name: pageResult.name,
      checks: mergedChecks,
      diagnostics: mergedDiagnostics,
      error: pageResult.error,
    };
  }

  const eventsRaw = await eventsFile.async('string');
  let userEvents: UserEvent[] = [];
  let parseErr: string | null = null;
  try {
    userEvents = JSON.parse(eventsRaw) as UserEvent[];
  } catch (err) {
    parseErr = err instanceof Error ? err.message : String(err);
  }

  if (parseErr !== null) {
    mergedChecks.push({
      name: 'A31.0b: logs/events.json parses as JSON',
      expected: 'JSON.parse success',
      actual: `<error: ${parseErr}>`,
      passed: false,
    });
    return {
      passed: false,
      name: pageResult.name,
      checks: mergedChecks,
      diagnostics: mergedDiagnostics,
      error: pageResult.error,
    };
  }

  const eventsContainingSentinel = userEvents.filter(
    (e) => typeof e.value === 'string' && e.value.includes(A31_PASSWORD_SENTINEL),
  );
  const eventsTargetingPassword = userEvents.filter(
    (e) => e.target === A31_PASSWORD_SELECTOR,
  );
  mergedDiagnostics.push(`A31 userEvents.length=${userEvents.length}`);
  mergedDiagnostics.push(
    `A31 sentinel-containing count=${eventsContainingSentinel.length}, password-targeting count=${eventsTargetingPassword.length}`,
  );

  mergedChecks.push({
    name: 'A31.2: 0 UserEvent entries contain the SENTINEL in their .value field (proves src/content/index.ts:82 filter fired)',
    expected: 0,
    actual: eventsContainingSentinel.length,
    passed: eventsContainingSentinel.length === 0,
  });
  mergedChecks.push({
    name: `A31.3: 0 UserEvent entries have target === '${A31_PASSWORD_SELECTOR}' (filter early-returns BEFORE addUserEvent)`,
    expected: 0,
    actual: eventsTargetingPassword.length,
    passed: eventsTargetingPassword.length === 0,
  });

  const mergedPassed = mergedChecks.every((c) => c.passed);
  return {
    passed: mergedPassed,
    name: pageResult.name,
    checks: mergedChecks,
    diagnostics: mergedDiagnostics,
    error: pageResult.error,
  };
}
```

2. Open `tests/uat/harness.test.ts`. In the import block from `./lib/harness-page-driver`, AFTER `driveA30,` and BEFORE `getManifestVersion,` add:

```typescript
  // Plan 03-03 — password-filter PARTIAL (SPEC §10 #8 PARTIAL per D-P3-02)
  driveA31,
```

3. AFTER the `driveA30Wrapped` const (added by Plan 03-02), add:

```typescript
  // Plan 03-03 — driveA31 needs downloadsDir for host-side JSZip
  // negative-assertion against logs/events.json.
  const driveA31Wrapped: (page: import('puppeteer').Page) => Promise<AssertionRecord> =
    (page) => driveA31(page, handles.downloadsDir);
```

4. In the drivers array, AFTER the `{ name: 'A30', ... }` entry, add:

```typescript
    // Plan 03-03 A31: password-filter PARTIAL (SPEC §10 #8 PARTIAL per
    // D-P3-02). Negative-assertion: types sentinel into password input;
    // host-side asserts absence from logs/events.json (proves the
    // existing src/content/index.ts:82 filter fires).
    { name: 'A31', drive: driveA31Wrapped },
```

5. Update the orchestrator banner line (line 268) to append `, A31`:

```typescript
  process.stdout.write('Architecture: A0 pre-flight + extension-internal page driver (A1..A14, A15..A17, A18..A22, A23, A24, A25, A26, A27, A28, A29, A30, A31)\n');
```

6. Run `npx tsc --noEmit`. Expected: clean.
7. Run `HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat`. Expected: `32/32 GREEN`.
  </action>
  <verify>
    <automated>npx tsc --noEmit; D=$(grep -c "driveA31" tests/uat/lib/harness-page-driver.ts); test "$D" -ge 2 &amp;&amp; H=$(grep -c "driveA31" tests/uat/harness.test.ts); test "$H" -ge 3 &amp;&amp; HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat</automated>
  </verify>
  <acceptance_criteria>
    - `npx tsc --noEmit` exits 0.
    - `grep -c 'driveA31' tests/uat/lib/harness-page-driver.ts` returns >=2.
    - `grep -c 'driveA31' tests/uat/harness.test.ts` returns >=3.
    - `grep -c 'secret-do-not-log-123' tests/uat/lib/harness-page-driver.ts` returns exactly 1.
    - `HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat` exits 0 with stdout containing `UAT harness: 32/32 assertions passed`.
    - `npm test -- --run tests/background/no-test-hooks-in-prod-bundle.test.ts` exits 0 (Tier-1 inventory stays at 12).
  </acceptance_criteria>
  <done>
    UAT harness runs 32/32 GREEN with A31 verifying the §10 #8 PARTIAL
    contract: typing into a password input produces zero events whose
    value contains the sentinel and zero events targeting the password
    selector. The existing src/content/index.ts:82 filter is the
    verified mechanism; full masking remains Out of Scope v1 per D-P3-02.
  </done>
</task>

</tasks>

<threat_model>
## Trust Boundaries

| Boundary | Description |
|----------|-------------|
| Puppeteer host ↔ page realm | Test harness drives via page.evaluate; production filter at src/content/index.ts:82 runs inside the page content script |
| Page realm ↔ content script | Synthetic input event dispatched on #probe-password reaches the production listener at src/content/index.ts:78 |
| Filter ↔ event log | Negative-assertion contract: filter at line 82 prevents value from reaching userEvents[] which is what assembles logs/events.json |
| dist-test/ ↔ dist/ | Two-bundle separation: Plan 03-03 adds NO test-only symbols; production bundle invariant unchanged |

## STRIDE Threat Register

| Threat ID | Category | Component | Disposition | Mitigation Plan |
|-----------|----------|-----------|-------------|-----------------|
| T-03-03-01 | Information Disclosure | Sentinel value lands in event log despite filter | mitigate | A31 IS the negative-assertion mitigation — RED A31 means the filter regressed; the test enforces the invariant. Sentinel is not a real secret (RESEARCH §"Security Domain"); if it leaked, it would be visible in events.json which is logged but never transmitted (REQ-password-confidentiality Out of Scope v1 charter applies). |
| T-03-03-02 | Information Disclosure | Test-only hook surface leaking to production bundle | mitigate | A31 rides the production input listener; no `__MOKOSH_UAT__`-gated symbols. FORBIDDEN_HOOK_STRINGS unchanged at 12 entries. |
| T-03-03-03 | Tampering | A31 SAVE produces a zip in the per-run downloadsDir that contains the sentinel only IF the filter regressed | accept | The per-run downloadsDir is mkdtempSync'd by launchHarnessBrowser + cleaned by the test runner; no cross-run leakage. Sentinel is not a real secret. |
| T-03-03-04 | Repudiation | If A31 GREEN but the production filter actually broke, the assertion would mislead | mitigate | A31 checks two orthogonal paths: (a) sentinel-value absence and (b) password-selector-target absence. Both pass IFF the filter early-returns BEFORE addUserEvent. A regression in the filter would cause AT LEAST ONE of the two checks to RED. Defense-in-depth at the test layer. |

No new production surface; threat surface unchanged from Phase 2. The
existing src/content/index.ts:82 filter is the verification subject;
the PARTIAL mark in Plan 03-05 VERIFICATION.md explicitly carries the
charter rationale.
</threat_model>

<verification>
- `npx tsc --noEmit` exits 0.
- `HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat` exits 0 with 32/32 GREEN.
- `npm test -- --run tests/background/no-test-hooks-in-prod-bundle.test.ts` exits 0 (12 FORBIDDEN_HOOK_STRINGS × 0 hits each).
- A31 diagnostic line shows `sentinel-containing count=0, password-targeting count=0`.
</verification>

<success_criteria>
- A31 GREEN with 3 merged checks (SAVE ack + 2 negative-assertions).
- The existing src/content/index.ts:82 password filter is verified to
  fire on synthetic input events into the probe-page password element.
- FORBIDDEN_HOOK_STRINGS unchanged at 12 entries.
- vitest baseline preserved (171/171 GREEN).
- Plan 03-05 VERIFICATION.md will mark §10 #8 as PARTIAL with explicit
  charter citation (D-P3-02) and reference A31 GREEN as the existing-
  minimum evidence.
</success_criteria>

<output>
After completion, create
`.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-03-SUMMARY.md`
documenting:
- Negative-assertion contract verified (2 orthogonal absence checks)
- D-P3-02 charter alignment (existing-minimum verification; not scope expansion)
- UAT 31 → 32 GREEN; Tier-1 inventory unchanged at 12
- Plan 03-04 wave dependency: SAME 3 harness files; SEQUENTIAL within Wave 2 per RESEARCH Pitfall 6
</output>
