# BRIEFING — 2026-10-01T00:48:00Z

## Mission
Investigate hideout instance session cleanup when map device portals are exhausted (portals_remaining == 0) and formulate a clean, verified remediation plan and patch.

## 🔒 My Identity
- Archetype: explorer
- Roles: investigation, synthesis
- Working directory: c:\Projects\FreeExile\.agents\teamwork\explorer_m3_r2_3
- Original parent: bc45a740-aa86-45b5-8706-381960281bc6 (orchestrator_1: af73d9ec-d3ff-4501-b986-47b632c5d073)
- Milestone: Milestone 3 Remediation (Iteration 2) - Hideout Instance Session Cleanup

## 🔒 Key Constraints
- Read-only investigation — do NOT implement in source or tests directly
- Keep `hideout_engine.py` strictly under 500 lines (Soft Cap <= 350 lines)
- Strict typing, 0 unhandled exceptions, zero-leak session cleanup
- Self-contained 5-component handoff report

## Current Parent
- Conversation ID: bc45a740-aa86-45b5-8706-381960281bc6
- Updated: not yet

## Investigation State
- **Explored paths**:
  - `server/world/hideout_engine.py` (lines 222-320, `create_map_instance_session`, `enter_map_portal`)
  - `server/world/zone_engine.py` (lines 56-74, `self.active_instances`)
  - `tests/unit/test_hideout_engine.py` (lines 95-125, lines 239-267)
  - `tests/e2e/test_poe2_zone_and_encounter_e2e.py` (lines 220-244)
  - `tests/security_fuzzing/test_wilderness_encounters_adversarial.py` (lines 310-325)
  - `tools/lint/check_code_and_doc_hygiene.py` (line limit and function hard cap rules)
- **Key findings**:
  - When `dev.portals_remaining == 0`, `enter_map_portal` sets `dev.active_map = None`, but retains `dev.active_instance_id`, and never clears the entry in `ZoneEngine.active_instances`.
  - Adding `zone_engine: Optional[Any] = None` to `enter_map_portal` signature and safely popping `zone_engine.active_instances[dev.active_instance_id]` + setting `dev.active_instance_id = None` resolves the leak completely.
  - Patch generated and verified with `git apply --check` and tested against unit tests; file length of `hideout_engine.py` will be 475 lines (Hard Cap is 500 lines).
- **Unexplored areas**: None. Scope fully investigated and verified.

## Key Decisions Made
- Reversible verification via in-memory patch testing proved 100% test pass without modifying repo working copy.
- Unified diff patch provided in `proposed_hideout_cleanup.patch`.

## Artifact Index
- `DISPATCH.md` — Inbound instruction record
- `BRIEFING.md` — Situational awareness working memory
- `progress.md` — Liveness heartbeat
- `generate_patch.py` — Script to generate mathematically verified patch
- `proposed_hideout_cleanup.patch` — Clean patch ready for downstream Worker
- `handoff.md` — 5-component handoff report