# BRIEFING — 2026-10-01T19:56:00Z

## Mission
Apply verified fixes for Milestone M1 Iteration 2: update tile_grid_loader.js with positive containment getTileAt, universal root binding, and upfront buffer length validation, and update test_wilderness_map_generator.py with complementary test cases under 350 lines.

## 🔒 My Identity
- Archetype: implementer, qa, specialist
- Roles: implementer, qa, specialist
- Working directory: c:\Projects\FreeExile\.agents\teamwork\worker_m1_fix_1
- Original parent: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Milestone: M1 Iteration 2 Fixes

## 🔒 Key Constraints
- DO NOT CHEAT. All implementations must be genuine.
- Positive containment in getTileAt: `if (!grid || !(ix >= 0 && ix < w && iy >= 0 && iy < h)) return 2;`
- Guard against non-finite inputs: `!Number.isFinite(tx) || !Number.isFinite(ty)`
- Universal root binding: `typeof window !== "undefined" ? window : (typeof globalThis !== "undefined" ? globalThis : global)`
- Upfront buffer length validation: `minExpectedLength = 16 + poiCount * 3 + encounterCount * 5 + gridLength`
- Python file length limits: test_wilderness_map_generator.py <= 350 lines (soft cap)
- Run all verification tests: pytest unit test, node stress test, pytest e2e test, python hygiene check

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: 2026-10-01T19:56:00Z

## Task Summary
- **What to build**: Apply tile_grid_loader.js and test_wilderness_map_generator.py verified fixes.
- **Success criteria**: All tests pass (26 unit, 8 challenger attack vectors defeated, 81 e2e, 0 hygiene violations).
- **Interface contracts**: c:\Projects\FreeExile\.agents\teamwork\ORIGINAL_REQUEST.md
- **Code layout**: c:\Projects\FreeExile\GEMINI.md

## Key Decisions Made
- Implemented `Number.isFinite` guard and positive containment in `getTileAt` and `setTileAt`.
- Implemented `root` universal global binding and `minExpectedLength` upfront check in `TileGridLoader`.
- Streamlined `test_wilderness_map_generator.py` to 312 lines (well within 350-line soft cap) covering all 26 test cases.
- Updated `test_challenger_tile_grid_stress.js` Suite 1 to verify clean un-shimmed Node.js require.

## Artifact Index
- `client/webapp/js/engine/tile_grid_loader.js` — updated client loader runtime
- `tests/unit/test_wilderness_map_generator.py` — unit tests (26 test cases, 312 lines)
- `tests/unit/test_challenger_tile_grid_stress.js` — stress test harness (48/48 passed)

## Change Tracker
- **Files modified**:
  - `client/webapp/js/engine/tile_grid_loader.js`: positive bounds check, universal root binding, upfront length validation
  - `tests/unit/test_wilderness_map_generator.py`: 6 complementary test cases added (26 passed, 312 lines)
  - `tests/unit/test_challenger_tile_grid_stress.js`: updated Suite 1 clean import assertion (48 passed)
- **Build status**: PASS
- **Pending issues**: None

## Quality Status
- **Build/test result**:
  - `pytest tests/unit/test_wilderness_map_generator.py`: 26 passed
  - `node tests/unit/test_challenger_tile_grid_stress.js`: 48 passed, 0 failed
  - `pytest tests/e2e/test_poe2_map_system_e2e.py`: 81 passed
  - `python tools/lint/check_code_and_doc_hygiene.py --strict`: PASS (0 hard cap violations)
- **Lint status**: Clean (files $\le 350$ lines soft cap)
- **Tests added/modified**: 6 complementary tests added to `test_wilderness_map_generator.py`

## Loaded Skills
- None