test: coverage for ambient reflex-channel logging + watch window/cap flags

Ship coverage audit (85%, gate PASS) named five gaps; the two substantive
cheap ones close here: the codex-D11 logChannel='reflex' path now has a
behavioral pin (events land on channel 'reflex' through the drained sink;
no logChannel → no events), and gbrain watch's --window-turns / --max-pages
flags are exercised (turn-1 attribution under window=1; cap to one page).
Remaining flagged-not-blocking: the wallclock-timeout branch (untestable
without >10s real-clock flake — same rationale as the arming pin),
formatResult's volunteer case (module-private), and the cycle purge wiring.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/retrieval-reflex.test.ts

@@ -289,3 +289,47 @@ describe('v0.43 (#2095) — rolling window extraction through assemble()', () =>
     });
   });
 });
+
+describe('ambient-channel event logging (codex D11 — logChannel: reflex)', () => {
+  test('resolver with logChannel logs channel=reflex events through the drained sink', async () => {
+    const { awaitPendingVolunteerEventWrites, _resetPendingVolunteerEventWritesForTests } =
+      await import('../src/core/context/volunteer-events.ts');
+    _resetPendingVolunteerEventWritesForTests();
+    await engine.executeRaw('DELETE FROM context_volunteer_events').catch(() => {});
+    await seed('people/alice-example', 'Alice Example', 'A founder.');
+
+    const block = await resolveEntitiesToPointers(
+      engine,
+      'default',
+      extractCandidates('what do you think about Alice Example?'),
+      { logChannel: 'reflex' },
+    );
+    expect(block).not.toBeNull();
+    const { unfinished } = await awaitPendingVolunteerEventWrites(5_000);
+    expect(unfinished).toBe(0);
+    const rows = await engine.executeRaw<{ channel: string; slug: string; match_arm: string }>(
+      'SELECT channel, slug, match_arm FROM context_volunteer_events',
+      [],
+    );
+    expect(rows.length).toBe(1);
+    expect(rows[0].channel).toBe('reflex');
+    expect(rows[0].slug).toBe('people/alice-example');
+    expect(rows[0].match_arm).toBe('title');
+  });
+
+  test('no logChannel → no events (the volunteer layer logs its own)', async () => {
+    await engine.executeRaw('DELETE FROM context_volunteer_events').catch(() => {});
+    await seed('people/alice-example', 'Alice Example', 'A founder.');
+    const block = await resolveEntitiesToPointers(
+      engine,
+      'default',
+      extractCandidates('about Alice Example'),
+      {},
+    );
+    expect(block).not.toBeNull();
+    const { awaitPendingVolunteerEventWrites } = await import('../src/core/context/volunteer-events.ts');
+    await awaitPendingVolunteerEventWrites(5_000);
+    const rows = await engine.executeRaw<{ channel: string }>('SELECT channel FROM context_volunteer_events', []);
+    expect(rows.length).toBe(0);
+  });
+});

test/watch-command.test.ts

@@ -125,3 +125,31 @@ describe('gbrain watch (#2095)', () => {
     expect(out.join('')).toContain('people/alice-example');
   });
 });
+
+describe('gbrain watch — window + cap flags (ship coverage G4)', () => {
+  test('--window-turns 1: fires on the mention turn itself; the pronoun follow-up adds nothing', async () => {
+    await seed('people/alice-example', 'Alice Example', 'Alice is a founder.');
+    const out = await watchRun(
+      [
+        'assistant: Alice Example led one last year.',
+        'user: what did she invest in?',
+      ],
+      ['--window-turns', '1', '--json'],
+    );
+    // Watch volunteers per turn: the entity fires at turn 1 (its mention
+    // turn). With window=1 the follow-up turn extracts nothing, so exactly
+    // one row exists and it carries turn 1 attribution.
+    expect(out.length).toBe(1);
+    expect(JSON.parse(out[0]).turn).toBe(1);
+  });
+
+  test('--max-pages 1 caps a multi-entity turn to one volunteered page', async () => {
+    await seed('people/alice-example', 'Alice Example', 'Founder.');
+    await seed('people/bob-sample', 'Bob Sample', 'Engineer.');
+    const out = await watchRun(
+      ['user: intro Alice Example to Bob Sample'],
+      ['--max-pages', '1', '--json'],
+    );
+    expect(out.length).toBe(1);
+  });
+});