# BRIEFING — 2026-10-01T22:13:00Z

## Mission
Adversarial empirical stress testing and independent verification of Minimap HUD 30 Hz throttling, pause freezing, anti-maphack combat target logic, and full regression test suite for Milestone M4 Fix 2.

## 🔒 My Identity
- Archetype: EMPIRICAL CHALLENGER
- Roles: critic, specialist
- Working directory: c:\Projects\FreeExile\.agents\teamwork\challenger_m4_fix_2
- Original parent: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Milestone: M4 Fix 2
- Instance: 2 of 2

## 🔒 Key Constraints
- Review-only — do NOT modify implementation code
- Run all verification code ourselves — empirical proof required
- If cannot reproduce empirically, it does not count
- Provide explicit verdict: APPROVE or REQUEST_CHANGES in handoff.md

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: 2026-10-01T22:13:00Z

## Review Scope
- **Files reviewed**:
  - `client/webapp/js/ui/minimap_hud.js`
  - `client/webapp/js/ui/war_fog.js`
  - `client/webapp/js/engine/monster_system.js`
  - `client/webapp/js/engine/world_renderer.js`
  - `tests/unit/test_fog_and_minimap.py`
  - `tests/unit/test_tile_collision.py`
  - `tests/unit/test_mobile_webapp_config.py`
  - `tests/e2e/test_poe2_map_system_e2e.py`
  - `tools/perf/map_render_benchmark.js`
  - `tests/unit/test_challenger_m4_2_minimap_stress.js`
  - `tests/unit/test_minimap_hud_empirical_stress.js`
  - `tests/unit/test_challenger_m4_fix_1_stress.js`
  - `tools/lint/check_code_and_doc_hygiene.py`

## Key Decisions Made
- Executed dedicated empirical test harness `tests/unit/test_minimap_hud_empirical_stress.js` (236 lines): verified 30 Hz throttling dynamically skips 75.83% of frames at 120 FPS, and pause freezing achieves 100% suspension (0 render calls, 0 canvas ops).
- Verified full non-regression test suite: 975/975 unit tests pass, 81/81 e2e tests pass, 14/14 fog/minimap tests pass, 11/11 tile collision tests pass, 15/15 mobile webapp config tests pass, map render benchmark passes with 0 re-bakes.
- Verified trimming of `tests/unit/test_challenger_m4_fix_1_stress.js` down to 483 lines (<= 500 lines Hard Cap).
- Ran `python tools/lint/check_code_and_doc_hygiene.py --strict`: confirmed 0 hard cap violations (exit code 0).
- Final verdict: APPROVE.

## Artifact Index
- `.agents/teamwork/challenger_m4_fix_2/DISPATCH.md` — Assignment
- `.agents/teamwork/challenger_m4_fix_2/BRIEFING.md` — Agent working memory
- `.agents/teamwork/challenger_m4_fix_2/progress.md` — Execution heartbeat
- `.agents/teamwork/challenger_m4_fix_2/handoff.md` — Final verification report and verdict
- `tests/unit/test_minimap_hud_empirical_stress.js` — Empirical stress harness for Minimap HUD (236 lines)

## Attack Surface
- **Hypotheses tested**:
  - 30 Hz throttling skips ~75% at 120 FPS: CONFIRMED (75.83% over 120 frames, 75.08% over 1200 frames).
  - Pause freezing completely halts canvas operations: CONFIRMED (0 calls, 0 ops).
  - Waypoint safe radius string assertions in world_renderer.js: CONFIRMED intact (lines 375-401).
  - Strict hygiene audit: CONFIRMED 0 violations (exit code 0).
- **Vulnerabilities found**: None.
- **Untested angles**: None within M4 scope.

## Loaded Skills
- None.