# BRIEFING — 2026-10-01T20:54:28Z

## Mission
Design and architect client/webapp/js/engine/boss_gate_controller.js with state machine (LOCKED, UNLOCKED, BREACHED), collision integration, dynamic tile mutation, visual seal rune, and proximity lore popup, strictly <= 200 lines.

## 🔒 My Identity
- Archetype: explorer
- Roles: investigation, synthesis
- Working directory: c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2
- Original parent: af73d9ec-d3ff-4501-b986-47b632c5d073
- Milestone: Milestone 3 (Wilderness Pack Spawning & Map Device Instances - Encounters & Ambush)
- Assigned Milestone M3.2: Boss Gate State Machine & Controller Architecture (Orchestrator 11)

## 🔒 Key Constraints
- Read-only investigation — do NOT implement
- Do NOT modify source code directly (only create reports/analysis in own folder)
- Strict compliance with GEMINI.md, PROJECT.md, and Handoff Protocol
- Mandatory check of Safe Haven zero-hostile rules (`can_spawn_hostile_monsters`)
- Hygiene rules: code <= 500 lines hard cap, docs <= 600 lines hard cap
- boss_gate_controller.js design target: <= 200 lines (Soft cap 350, Hard cap 500 lines)
- ES Module with clean Node.js require compatibility

## Current Parent
- Conversation ID: 1cc48fc5-ce57-4f48-8964-24cab4bfcacc
- Updated: 2026-10-01T20:54:28Z

## Investigation State
- **Explored paths**:
  - `c:\Projects\FreeExile\.agents\teamwork\orchestrator_11\PROJECT.md`
  - `c:\Projects\FreeExile\.agents\teamwork\ORIGINAL_REQUEST.md` (R3 & R5)
  - `client/webapp/js/engine/tile_grid_loader.js` (header bytes 10-11, `setTileAt`, `getTileAt`)
  - `client/webapp/js/engine/tile_map_renderer.js` (`markChunkDirty`, tile palettes, chunk baking)
  - `client/webapp/js/engine/collision_engine.js` (`isPositionBlocked`, sliding physics)
  - `client/webapp/js/engine/world_renderer.js` & `canvas_renderer.js` (rendering pipelines)
  - `server/world/map_data_types.py` (`TileType.BOSS_GATE` = 10, `FLOOR` = 1, `VOID` = 0)
  - `tests/e2e/test_poe2_map_system_e2e.py` (boss gate breach tests)
- **Key findings**:
  - `TileGridLoader.loadBinaryMap` sets `bossGate: { x, y }` from bytes 10-11.
  - `setTileAt` in `tile_grid_loader.js` already integrates with `TileMapRenderer.markChunkDirty`.
  - Boss gate coordinates can be obtained from metadata or dynamically scanned (codes 10 / 15).
  - Designed complete reference implementation `proposed_boss_gate_controller.js` in 199 lines.
  - Verified with automated Node.js test harness covering all states, collision, mutation, rendering, and proximity.
- **Unexplored areas**: None within M3-2 scope.

## Key Decisions Made
- `BossGateState`: `LOCKED`, `UNLOCKED`, `BREACHED` enum.
- In `LOCKED`, `isPositionBlocked(wx, wy, radius)` treats the $(gx, gy)$ tile bounding box as impassable.
- Dynamic unlocking mutates $(gx, gy)$ to `FLOOR` (1 / 0) via `setTileAt` and marks chunk dirty.
- Proximity lore popup triggers at $\le 3.0$ tiles and deactivates at $> 3.5$ tiles (0.5-tile hysteresis).
- Auto-breach triggers when player enters gate (distance $< 0.8$ tiles) in `UNLOCKED` state.
- Render hook draws 2.5D isometric pulsating cyan/gold floor aura with rotating gold outer ring, counter-rotating cyan diamond sigil, and center gem.
- Full compatibility with Node.js `require()` and ES `import`.

## Artifact Index
- `c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2\DISPATCH.md` — Incoming dispatch log
- `c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2\BRIEFING.md` — Persistent working memory
- `c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2\progress.md` — Heartbeat and status
- `c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2\proposed_boss_gate_controller.js` — Complete, tested reference implementation (199 lines)
- `c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2\report.md` — Detailed technical architecture report
- `c:\Projects\FreeExile\.agents\teamwork\explorer_m3_2\handoff.md` — 5-component handoff report