# BRIEFING — 2026-10-02T02:37:00Z

## Mission
Adversarially challenge and stress-test the 30 map style assets in `client/webapp/assets/map/styles/` across loading times, edge cases (corrupt/zero-byte/truncated files), memory footprint (< 500 KB active biome, < 8 MB all 30 styles), and execute empirical tests with evidence.

## 🔒 My Identity
- Archetype: challenger
- Roles: critic, specialist
- Working directory: c:\Projects\FreeExile\.agents\teamwork\challenger_m2
- Original parent: 327366ba-dd05-4805-b53b-659a199b1450
- Milestone: Milestone 2 (Assets)
- Instance: 1 of 1

## 🔒 Key Constraints
- Review-only — do NOT modify implementation code
- Must run verification code independently; empirical evidence required
- Write adversarial test script, execute it, and record evidence
- Store agent metadata only in `.agents/teamwork/challenger_m2/`

## Current Parent
- Conversation ID: 327366ba-dd05-4805-b53b-659a199b1450
- Updated: 2026-10-02T02:37:00Z

## Review Scope
- **Files to review**: `client/webapp/assets/map/styles/**` (30 style directories, 360 assets)
- **Interface contracts**: `PROJECT.md`, `worker_m2/handoff.md`
- **Review criteria**: Asset decompression & load times, adversarial edge cases (corrupt, zero-byte, truncated, non-existent), memory footprint (< 500 KB active biome, < 8 MB total), PNG validity, normal map integrity

## Attack Surface
- **Hypotheses tested**: 
  - Assumption 1: All 360 PNGs are valid RGBA images and decompress without error or warning. -> CONFIRMED (100% pass, 0 corrupt files).
  - Assumption 2: Loading and decompressing an entire biome texture set takes < 15ms and memory footprint is < 500 KB uncompressed raw RGBA. -> CONFIRMED (Average biome switch 4.88 ms; active biome footprint exactly 416.00 KB < 500 KB).
  - Assumption 3: Total memory for all 30 styles is < 8 MB. -> CONFIRMED (Total on-disk is 1.57 MB < 8 MB; in-memory albedo textures for all 30 styles is 6.09 MB < 8 MB).
  - Assumption 4: Broken/corrupted PNGs, truncated streams, zero-byte files, missing files do not cause unhandled crashes in loaders. -> CONFIRMED (All 11 corruption/truncation/traversal variants trapped cleanly).
  - Assumption 5: Normal map Blue channel B > 128 holds strictly across all 120 normal map textures with no degenerate (0,0,0) or inverted normals. -> CONFIRMED (100% pass, mean B range 180.5 - 255.0).
- **Vulnerabilities found**: None in asset files. Minor note: Client JS catalog prototype property collisions (`constructor`, `toString`) are handled at catalog layer, not asset layer.
- **Untested angles**: GPU Metal compute shader pipeline memory allocation on physical Apple Silicon hardware (tested via software emulation and pixel buffer analysis).

## Loaded Skills
- None requested

## Key Decisions Made
- Created dedicated empirical adversarial test harness `tests/unit/test_map_styles_adversarial_stress.py` (274 lines, 20 test cases, 100% pass in 1.53s, 0 hygiene violations).
- Verified full test suite of 300 map style unit tests (100% pass in 3.79s).
- Verdict: APPROVE Milestone 2 assets.

## Artifact Index
- `.agents/teamwork/challenger_m2/DISPATCH.md` — Incoming dispatch log
- `.agents/teamwork/challenger_m2/BRIEFING.md` — Agent briefing & working memory
- `.agents/teamwork/challenger_m2/progress.md` — Heartbeat and progress tracking
- `.agents/teamwork/challenger_m2/handoff.md` — Adversarial test report & verdict
- `tests/unit/test_map_styles_adversarial_stress.py` — Adversarial stress test suite