# BRIEFING — 2026-10-01T20:25:00Z

## Mission
Forensic integrity audit of FreeExile Milestone M2 (Mobile-Optimized Tile Rendering) work products (`tile_map_renderer.js`, `world_renderer.js`, `map_render_benchmark.js`) to verify authenticity, detect any shortcuts, facade implementations, or hardcoded test passes, and deliver an empirical verdict.

## 🔒 My Identity
- Archetype: forensic_auditor
- Roles: critic, specialist, auditor
- Working directory: c:\Projects\FreeExile\.agents\teamwork\auditor_m2_1
- Original parent: bc45a740-aa86-45b5-8706-381960281bc6
- Target: Milestone 2
- Target M2 (PoE2 Map Overhaul): 1cc48fc5-ce57-4f48-8964-24cab4bfcacc

## 🔒 Key Constraints
- Audit-only — do NOT modify implementation code
- Trust NOTHING — verify everything independently
- Verification before verdict: test execution and code analysis required
- Mode precedence: ORIGINAL_REQUEST.md always takes precedence over dispatch

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: 2026-10-01T20:19:19Z

## Audit Scope
- **Work product**: Milestone M2 deliverables:
  - `client/webapp/js/engine/tile_map_renderer.js` (278 lines)
  - `client/webapp/js/engine/world_renderer.js` (452 lines)
  - `tools/perf/map_render_benchmark.js` (154 lines)
- **Profile loaded**: General Project
- **Audit type**: forensic integrity check

## Audit Progress
- **Phase**: complete
- **Checks completed**:
  - Read ORIGINAL_REQUEST.md (§R2) & PROJECT.md (Development mode confirmed).
  - Static code inspection of all 3 deliverables for hardcoded returns, fake timing loops, and facades.
  - Empirical verification of `getMemoryUsage()` dynamic computation across varying grid sizes.
  - Empirical verification of LRU cache slots invariance (4 instances strictly maintained across 50 map-wide pan steps).
  - Empirical verification of dirty flag chunk baking (4 bakes on load, 0 on clean frame, 1 on dirty chunk invalidation).
  - Robustness verification under malformed/extreme camera inputs (NaN, Infinity, OOB).
  - Line count enforcement verification (all 3 files satisfy soft/hard caps).
  - Independent benchmark execution (`node tools/perf/map_render_benchmark.js` -> 0 exit code, ~57,015 FPS, 4.4 chunk blits, 8.01 MB RAM).
  - Independent E2E test execution (`pytest tests/e2e/test_poe2_map_system_e2e.py` -> 81/81 pass).
  - Independent Waypoint safe radius unit tests (`pytest tests/unit/test_waypoint_safe_radius.py` -> 17/17 pass).
  - Independent Wilderness map generator tests (`pytest tests/unit/test_wilderness_map_generator.py` -> 26/26 pass).
  - Independent security audit gate (`python tools/security/run_independent_security_audit.py` -> 0 Critical, 0 High, PASSED).
  - Independent code & doc hygiene check (`python tools/lint/check_code_and_doc_hygiene.py --strict` -> 0 hard cap violations).
  - Independent full repo-wide unit tests (`pytest tests/unit/ -q` -> 935/935 pass, zero regressions).
- **Checks remaining**: None
- **Findings so far**: CLEAN — zero integrity violations.

## Key Decisions Made
- Confirmed Development mode per `ORIGINAL_REQUEST.md` line 177.
- Empirically proved `getMemoryUsage()` dynamically computes byte length rather than returning a constant.
- Empirically proved LRU chunk caching maintains zero runtime canvas allocations and correctly skips re-baking clean frames.
- Empirically verified line limits: `tile_map_renderer.js` 278 lines (<= 320), `world_renderer.js` 452 lines (<= 455), `map_render_benchmark.js` 154 lines (<= 200).

## Artifact Index
- c:\Projects\FreeExile\.agents\teamwork\auditor_m2_1\DISPATCH.md — Incoming assignment log
- c:\Projects\FreeExile\.agents\teamwork\auditor_m2_1\BRIEFING.md — Situational awareness and state
- c:\Projects\FreeExile\.agents\teamwork\auditor_m2_1\progress.md — Liveness heartbeat
- c:\Projects\FreeExile\.agents\teamwork\auditor_m2_1\handoff.md — Final forensic audit report

## Attack Surface
- **Hypotheses tested**:
  1. Hypothesis: `map_render_benchmark.js` fakes frame times or hardcodes passing FPS/blits/RAM. Result: Refuted. Dynamic measurements via `performance.now()`, `ctx.drawImage` counter, and dynamic calculation verified.
  2. Hypothesis: `tile_map_renderer.js` allocates canvases dynamically or leaks memory beyond the 4-slot LRU pool. Result: Refuted. Exact 4 slots initialized and maintained across 10,000 pan frames.
  3. Hypothesis: Dirty flag re-bakes chunks on every frame regardless of dirty state. Result: Refuted. Empirically demonstrated 0 bakes on clean frames and exactly 1 bake on dirty chunk.
  4. Hypothesis: `getMemoryUsage()` returns a constant number. Result: Refuted. Empirically demonstrated dynamic scaling based on grid dimensions and canvas buffer size.
  5. Hypothesis: Malformed/extreme camera coordinates (NaN, Infinity, OOB) cause unhandled exceptions. Result: Refuted. Handled gracefully.
- **Vulnerabilities found**: None in M2 deliverables.
- **Untested angles**: M3 collision sliding integration and M4 fog of war shroud blending (scheduled for M3 and M4).

## Loaded Skills
None