# BRIEFING — 2026-10-02T02:19:00Z

## Mission
Adversarial Verification of Reactive Language Switching in Chat UI (FreeExile client).

## 🔒 My Identity
- Archetype: challenger
- Roles: critic, specialist
- Working directory: c:\Projects\FreeExile\.agents\teamwork\challenger_i18n_m1_1
- Original parent: 0361e281-a64e-4264-a674-2b16c804009d
- Milestone: m1_1
- Instance: 1 of 1

## 🔒 Key Constraints
- Review-only — do NOT modify implementation code
- Empirical challenger: must write and execute tests / stress harnesses; cannot rely on worker claims
- Report failures as findings; do not fix them directly
- Write only to own folder (.agents/teamwork/challenger_i18n_m1_1) for metadata/reports, and tests to proper project test directory (e.g. tests/)

## Current Parent
- Conversation ID: 0361e281-a64e-4264-a674-2b16c804009d
- Updated: 2026-10-02T02:19:00Z

## Review Scope
- **Files reviewed**:
  - `client/webapp/js/data/i18n.js` (343 lines)
  - `client/webapp/js/data/chat_i18n_catalog.js` (395 lines)
  - `client/webapp/js/data/i18n_catalog.js` (634 lines)
  - `client/webapp/js/ui/chat_ui.js` (347 lines)
  - `client/webapp/index.html` (199 lines)
  - `worker_m1_1/implementation_report.md`
  - `worker_m1_1/handoff.md`
- **Interface contracts**: `PROJECT.md`, `ORIGINAL_REQUEST.md` (## 2026-10-02T01:42:06Z)
- **Review criteria**: Live programmatic locale switching, synchronous DOM updates, rapid sequential switching stress, invalid/unknown locale fallbacks.

## Attack Surface
- **Hypotheses tested**:
  1. Live programmatic switching without reload updates all 8 tabs, active placeholder, send button, and cooldown badge across all 9 languages (`vi`, `en`, `zh`, `ja`, `ko`, `th`, `de`, `ru`, `es`). -> PASS
  2. Switching channels and permission states dynamically updates restriction microcopy. -> PASS
  3. Cooldown badge reflects locked and wait states reactively. -> PASS
  4. Open item tooltips re-render in-place when language changes. -> PASS
  5. Chat log history messages and channel tags re-render reactively. -> PASS
  6. Rapid switching stress: 1,000 rapid switches execute in < 500ms SLA without listener leak. -> PASS (47ms, 0 leak)
  7. Invalid/unknown locales ('xx', null, undefined, '') fall back gracefully to English/Vietnamese dictionaries without uncaught exceptions or undefined text. -> PASS
  8. Listener error isolation: throwing subscriber does not break subsequent listeners or event dispatch; unsubscription cleans up listener properly. -> PASS
  9. Cross-tab `storage` event triggers locale synchronization and UI re-render. -> PASS
- **Vulnerabilities found**: None. System is resilient and conforms strictly to contracts.
- **Untested angles**: Hardware-level browser memory pressure on mobile devices under low-memory conditions (handled by small DOM footprint).

## Loaded Skills
- None assigned.

## Key Decisions Made
- Authored empirical test suite in `tests/unit/test_challenger_i18n_reactive_chat.py` (275 lines, 9 tests, 100% pass).
- Strict adherence to file line limits: test file (275 lines <= 350 soft cap), all modified client files strictly below soft caps.
- Final verdict: CONFIRM_CORRECT.

## Artifact Index
- DISPATCH.md — dispatch recording
- BRIEFING.md — persistent state memory
- progress.md — liveness heartbeat
- challenge_report.md — adversarial review report
- handoff.md — 5-component handoff report