# Forensic Audit Report: Milestone M3 Deliverables

**Agent**: `auditor_m3_1` (Forensic Integrity Auditor)  
**Parent**: `1cc48fc5-ce57-4f48-8964-24cab4bfcacc` (`parent`)  
**Timestamp**: 2026-10-01T21:19:00Z  
**Work Product**: Milestone M3 Deliverables
- `client/webapp/js/engine/collision_engine.js`
- `client/webapp/js/engine/boss_gate_controller.js`
- `server/world/zone_engine.py`
- `server/world/procedural_map_engine.py`
- `tests/unit/test_tile_collision.py`

**Profile**: General Project  
**Integrity Mode**: `development` (per `ORIGINAL_REQUEST.md` ## 2026-10-01T19:19:13Z; verified compliant also under `demo` and `benchmark`)  
**Verdict**: **CLEAN**

---

## 1. Observation

### 1.1 Source Code Static Analysis & Non-Cheating
1. **Circle-AABB Mathematical Clamping (`client/webapp/js/engine/collision_engine.js` lines 90-105)**:
   ```javascript
   const tx0 = Math.floor(wx - radius), tx1 = Math.floor(wx + radius);
   const ty0 = Math.floor(wy - radius), ty1 = Math.floor(wy + radius);
   const radSq = radius * radius;

   for (let ty = ty0; ty <= ty1; ty++) {
     for (let tx = tx0; tx <= tx1; tx++) {
       const tile = getTile(tx, ty);
       if (isTileBlocked(tile, isDodge, tx, ty)) {
         const cx = wx < tx ? tx : (wx > tx + 1 ? tx + 1 : wx);
         const cy = wy < ty ? ty : (wy > ty + 1 ? ty + 1 : wy);
         const dx = wx - cx, dy = wy - cy;
         if (dx * dx + dy * dy < radSq) return true;
       }
     }
   }
   ```
   *Direct Observation*: Evaluates exact continuous distance from character center $(wx, wy)$ to the clamped bounding box of each spanned tile $[tx, tx+1] \times [ty, ty+1]$. No hardcoded values, lookup shortcuts, or simulated responses.

2. **Zero-Heap 2-Axis Wall Sliding (`client/webapp/js/engine/collision_engine.js` lines 146-175)**:
   - Tests direct target first. If blocked, tests orthogonal single-axis movement ($X$ then $Y$).
   - If both single axes are clear (approaching an exterior corner), selects the dominant axis ($\max(|dx|, |dy|)$) to avoid re-combining into the corner.
   - Reuses module-level `SLIDE_RESULT = { wx: 0, wy: 0, isSliding: false }` to avoid object allocation in the 120 FPS hot path.

3. **Boss Gate State Machine & Dynamic Tile Mutation (`client/webapp/js/engine/boss_gate_controller.js` lines 68-88)**:
   ```javascript
   unlock(floorTileCode = 1) {
     if (this.state !== BossGateState.LOCKED) return false;
     this.state = BossGateState.UNLOCKED;

     if (this.gateX !== null && this.gateY !== null) {
       if (typeof root.setTileAt === "function") {
         root.setTileAt(this.gateX, this.gateY, floorTileCode);
       } else if (root.currentMapGrid) {
         const w = root.currentMapWidth || 0;
         root.currentMapGrid[this.gateY * w + this.gateX] = floorTileCode;
         if (root.TileMapRenderer?.markChunkDirty) root.TileMapRenderer.markChunkDirty(this.gateX, this.gateY);
       }
     }
   ```
   *Direct Observation*: Genuinely mutates the underlying `currentMapGrid` array to `FLOOR` (1) and marks the containing chunk dirty in `TileMapRenderer` to trigger texture re-baking.

4. **Server Tile Terrain Spawn Validation (`server/world/zone_engine.py` lines 126-158)**:
   ```python
   if tx is not None and ty is not None:
       from server.world.procedural_map_engine import ProceduralMapEngine
       from server.world.map_data_types import TileType
       tile_type = ProceduralMapEngine.get_tile_type(zone_id, tx, ty)
       if tile_type in (TileType.WALL, TileType.CHASM, TileType.WATER, TileType.BOSS_GATE, TileType.VOID) or not tile_type.is_passable():
           return (
               False,
               f"Nghiêm cấm sản sinh quái vật trên địa hình không thể đi qua [{tile_type.name}] tại ({tx}, {ty})!",
           )
   ```
   *Direct Observation*: Queries `ProceduralMapEngine.get_tile_type(zone_id, tx, ty)` dynamically. Blocks `WALL`, `CHASM`, `WATER`, `BOSS_GATE`, and `VOID`. Also enforces Safe Haven purity (`zone_player_hideout` and `zone_boundless_sanctuary` unconditionally reject hostile spawns).

### 1.2 Line Counts and Code Hygiene
- `client/webapp/js/engine/collision_engine.js`: 232 lines (Strict limit: $\le 320$ lines) -> **PASS**
- `client/webapp/js/engine/boss_gate_controller.js`: 199 lines (Strict limit: $\le 200$ lines) -> **PASS**
- `server/world/zone_engine.py`: 482 lines (Strict limit: $\le 490$ lines) -> **PASS**
- `server/world/procedural_map_engine.py`: 445 lines (Strict limit: $\le 450$ lines) -> **PASS**
- `tests/unit/test_tile_collision.py`: 165 lines (Strict limit: $\le 300$ lines) -> **PASS**
- `python tools/lint/check_code_and_doc_hygiene.py --strict`:
  ```
  Tổng số file đã quét      : 555
   - File mã nguồn (code)   : 434
   - File tài liệu (docs)   : 121
   - File đạt chuẩn sạch sẽ : 520
  ================================================================================
  ✅ KẾT QUẢ: TOÀN BỘ MÃ NGUỒN VÀ TÀI LIỆU TUÂN THỦ HARD CAP HYGIENE!
  ================================================================================
  ```
  Exit code 0. Zero hard-cap violations repository-wide. -> **PASS**

### 1.3 Independent Execution Verification
1. `pytest tests/unit/test_tile_collision.py -v`:
   - 11/11 tests passed in 0.15s. -> **PASS**
2. `pytest tests/e2e/test_poe2_map_system_e2e.py -v`:
   - 81/81 tests passed in 1.19s. -> **PASS**
3. `pytest tests/unit/test_waypoint_safe_radius.py tests/unit/test_wilderness_map_generator.py -v`:
   - 43/43 tests passed in 1.35s. -> **PASS**
4. `node tools/perf/map_render_benchmark.js`:
   - Stationary Test: 0 re-bakes over 50 frames (Target: 0).
   - Equivalent Average FPS: 143,260.3 FPS (Target $\ge 30.0$ FPS).
   - Draw calls per frame: avg 6.41 $\le 6.5$, max 8 $\le 8$.
   - Final Benchmark Verdict: **APPROVE**. -> **PASS**
5. `pytest tests/unit/ -q`:
   - 946 passed in 81.24s with zero regressions. -> **PASS**

### 1.4 Adversarial Stress Testing Results
1. **Non-Finite & Boundary Coordinates**:
   - `isPositionBlocked(NaN, 5.0)` -> `true` (Correctly blocked).
   - `isPositionBlocked(5.0, Infinity)` -> `true` (Correctly blocked).
   - `isPositionBlocked(-0.5, 5.0)` -> `true` (Out of bounds blocked).
   - `isPositionBlocked(10.5, 5.0)` on a 10x10 grid -> `true` (Out of bounds blocked).
2. **Proximity Hysteresis & State Transitions**:
   - At distance $\le 3.0$ tiles: `isProximityActive = true`, popup displayed.
   - At distance $\in (3.0, 3.5]$ tiles: `isProximityActive` remains `true` (hysteresis prevents flicker).
   - At distance $> 3.5$ tiles: `isProximityActive = false`, popup hidden.
   - At distance $< 0.8$ tiles while `UNLOCKED`: transitions to `BREACHED`.
3. **Server Spawn Validation**:
   - Negative coordinates $(tx=-1, ty=-1)$ return `(False, "Nghiêm cấm sản sinh quái vật trên địa hình không thể đi qua [WALL] tại (-1, -1)!")`.
   - Sanctuary/Hideout zones return `False` under Safe Haven purity.
   - Positional arguments `(zone_id, tx, ty)` correctly validate.

---

## 2. Logic Chain

1. **Premise 1 (Authenticity)**: If an implementation relies on real mathematical formulas ($cx = \text{clamp}(wx, tx, tx+1)$, $(wx-cx)^2 + (wy-cy)^2 < r^2$), mutates memory buffers dynamically (`currentMapGrid[idx] = floorTileCode`), and evaluates game state in real-time without hardcoded values, it is not a facade.
2. **Observation 1**: `collision_engine.js` executes continuous Circle-AABB clamping and dominant-axis sliding physics.
3. **Observation 2**: `boss_gate_controller.js` implements a 3-state FSM (`LOCKED`, `UNLOCKED`, `BREACHED`) with authentic buffer mutation and cache invalidation.
4. **Observation 3**: `zone_engine.py` dynamically resolves tile passability via `ProceduralMapEngine.get_tile_type` and rejects spawns on impassable terrain or within Safe Havens.
5. **Premise 2 (Hygiene & Caps)**: All modified files comply with the quantitative limits: `collision_engine.js` (232 $\le$ 320), `boss_gate_controller.js` (199 $\le$ 200), `zone_engine.py` (482 $\le$ 490), `procedural_map_engine.py` (445 $\le$ 450), `test_tile_collision.py` (165 $\le$ 300), and `check_code_and_doc_hygiene.py --strict` returns 0 violations.
6. **Premise 3 (Empirical Verification)**: 100% of unit tests (11/11 collision tests, 946/946 full suite tests) and E2E tests (81/81 map tests) pass in an independent test execution environment.
7. **Conclusion**: The deliverables satisfy all architectural, mathematical, and integrity criteria without shortcuts or fabrication.

---

## 3. Caveats

- **No caveats**: All 5 deliverables have been empirically verified. All tests, benchmarks, linters, and adversarial edge cases pass with zero errors.

---

## 4. Conclusion

Milestone M3 deliverables are verified to be fully authentic, robust, compliant with line limits, and free of facades or hardcoded values.

**Final Verdict**: **CLEAN**

---

## 5. Verification Method

To independently reproduce this audit:

```bash
# 1. Check line caps and strict repo hygiene
python tools/lint/check_code_and_doc_hygiene.py --strict

# 2. Run tile collision unit test suite (11 tests)
pytest tests/unit/test_tile_collision.py -v

# 3. Run PoE2 procedural map E2E suite (81 tests)
pytest tests/e2e/test_poe2_map_system_e2e.py -v

# 4. Run waypoint safe radius and map generator suites (43 tests)
pytest tests/unit/test_waypoint_safe_radius.py tests/unit/test_wilderness_map_generator.py -v

# 5. Run mobile map renderer benchmark
node tools/perf/map_render_benchmark.js

# 6. Run full unit test suite (946 tests, zero regressions)
pytest tests/unit/ -q
```