# AD-641b Build Report — Ward Room Hebbian Learning v1 (Router Only)

**Prompt:** `prompts/ad-641b-ward-room-hebbian.md`
**Builder:** Builder agent (Wave 9A, prompt 2 of 3)
**Date:** 2026-05-02
**Status:** ✅ Complete

## Files Changed

- `src/probos/events.py` (+2) — 2 new EventTypes
- `src/probos/cognitive/ward_room_hebbian/__init__.py` (+5) — package init
- `src/probos/cognitive/ward_room_hebbian/router.py` (+105) — router module
- `src/probos/config.py` (+8) — `WardRoomHebbianConfig` + SystemConfig field
- `src/probos/startup/finalize.py` (+13) — startup wiring after observability bridge
- `tests/test_ad641b_ward_room_hebbian.py` (+115) — 11 new tests
- `PROGRESS.md`, `DECISIONS.md`, `docs/development/roadmap.md` — tracker updates

## Sections Implemented

- ✅ Section 0: Event Types
- ✅ Section 1: Package init
- ✅ Section 2: WardRoomHebbianRouter
- ✅ Section 3: Listener wholesale-deferred to AD-641b-iv (per spec — no code shipped, no `listener.py`, no `ward_room_endorsement_listener` runtime attribute)
- ✅ Section 4: WardRoomHebbianConfig
- ✅ Section 5: Startup wiring
- ✅ Section 6: 11 tests

## Post-Build Section Audit

Section 3 ships zero code by design (deferral stub). All other sections have corresponding code.

Verified no listener artifacts:
- No `src/probos/cognitive/ward_room_hebbian/listener.py`
- No `WardRoomEndorsementListener` symbol anywhere in src/
- No `ward_room_endorsement_listener` attribute set on runtime

## Test Results

- Focused (`-n 0`): 11/11 passed in 0.26s
- Mesh Hebbian regression (`test_hebbian_social.py + test_hebbian_source_key.py`): 10/10 passed in 20.84s
- Full gate (`-n 8 --dist=loadfile`): **10590 passed + 15 skipped, no failures**

Test count delta: 10579 → 10590 (+11 new).

## Deferred Nits

None.
