# BRIEFING — 2026-10-01T20:51:00Z

## Mission
Independently review and stress-test Milestone M2 Iteration 2 remediation changes in tile_map_renderer.js and map_render_benchmark.js, verify tests, check integrity, and issue an evidence-based verdict.

## 🔒 My Identity
- Archetype: teamwork_preview_reviewer
- Roles: reviewer, critic
- Working directory: c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_fix_1
- Original parent: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Milestone: M2 Iteration 2 Fix
- Instance: 1 of 1

## 🔒 Key Constraints
- Review-only — do NOT modify implementation code
- Check for integrity violations (hardcoded test results, facade implementations, shortcut bypasses, fabricated logs, self-certifying work)
- Verify code limits: tile_map_renderer.js <= 320 lines (Soft 350, Hard 500), map_render_benchmark.js <= 200 lines
- Write only to .agents/teamwork/reviewer_m2_fix_1/
- Issue verdict APPROVE or REQUEST_CHANGES

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: 2026-10-01T20:47:02Z

## Review Scope
- **Files to review**:
  - `client/webapp/js/engine/tile_map_renderer.js`
  - `tools/perf/map_render_benchmark.js`
- **Interface contracts**: `c:\Projects\FreeExile\.agents\teamwork\orchestrator_11\PROJECT.md`, `c:\Projects\FreeExile\GEMINI.md`, `c:\Projects\FreeExile\AGENTS.md`
- **Review criteria**: correctness, 4-plane SAT diamond culling, LRU cache sizing (MAX_SLOTS = 8), 0x0 viewport & bounds guards, Node/ESM compatibility, line count limits, test verification

## Review Checklist
- **Items reviewed**:
  - `client/webapp/js/engine/tile_map_renderer.js` (294 lines, SAT culling, 8-slot LRU, edge guards)
  - `tools/perf/map_render_benchmark.js` (187 lines, 0-bake static test, 1000 frame pan, RAM budget check)
  - `tools/perf/stress_test_lru_cache.js` (373 lines, 8 gates, 10k frames)
- **Verdict**: APPROVE
- **Unverified claims**: 0 remaining. All claims verified through direct independent execution.

## Attack Surface
- **Hypotheses tested**:
  - LRU cache thrashing across entire 120x90 map at sub-tile resolution (13,231 points tested -> 0 thrashing points)
  - Mobile landscape ($844 \times 390$) frustum culling behavior (max 7 chunks visible)
  - 0x0 viewport, negative viewport, null/undefined arguments, NaN/Infinity camera coords (all passed)
  - All 0..255 TileType codes fallback handling (passed)
  - RAM exactness calculation (passed: 16.010 MB)
- **Vulnerabilities found**: None. Integrity checks confirmed real logic, zero facades, zero hardcoded values.
- **Untested angles**: Full WebGL/Canvas2D GPU rasterization on physical hardware (covered by standard synthetic and unit testing).

## Key Decisions Made
- Confirmed mathematical validity of 4-plane Separating Axis Theorem (SAT) culling.
- Verified LRU pool capacity of 8 slots guarantees zero thrashing across all possible camera coordinates in portrait mobile ($390 \times 844$).
- Verified all 7 test suites pass with 100% exit code 0.
- Issued verdict: APPROVE.

## Artifact Index
- `c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_fix_1\BRIEFING.md` — persistent working memory
- `c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_fix_1\DISPATCH.md` — dispatch instructions
- `c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_fix_1\progress.md` — liveness heartbeat
- `c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_fix_1\adversarial_test.js` — adversarial test script
- `c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_fix_1\handoff.md` — final handoff report