feat(tests): pytest-asyncio test suite — 119 tests across 3 modules

Infrastructure (T01):
- tests/conftest.py: sync schema setup (psycopg2), per-test table
  truncation, async ASGI client with get_session override
- pyproject.toml: [tool.pytest.ini_options] asyncio_mode=auto
- Makefile: make test target with TEST_DATABASE_URL

Core router tests (T02): 19 tests
- domains, topics, workstreams, tasks, decisions + state summary
- Caught real bug: topic router missing duplicate-slug 409 guard (fixed)

TD/EP/Contributions/SBOM tests (T03): 10 tests
- CRUD + status transitions + lifecycle guard + SBOM ingest

MCP smoke tests (T04): 12 tests
- get_state_summary, create_task, update_task_status,
  add_progress_event, flag_for_human HTTP shapes

CI gate (T05): make test documented in CLAUDE.md session protocol

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Makefile

@@ -1,4 +1,4 @@
-.PHONY: install install-cli db db-tools migrate seed api dashboard check start clean register-project validate-adr add-domain rename-domain add-repo list-repos register-path cleanup-stale tunnel tunnel-daemon tunnel-loop tunnel-status tunnel-stop install-hooks install-hooks-all gitea-inventory
+.PHONY: install install-cli db db-tools migrate seed api dashboard check test start clean register-project validate-adr add-domain rename-domain add-repo list-repos register-path cleanup-stale tunnel tunnel-daemon tunnel-loop tunnel-status tunnel-stop install-hooks install-hooks-all gitea-inventory
 
 COMPOSE = docker compose -f infra/docker-compose.yml --env-file .env
 
@@ -41,6 +41,10 @@ dashboard:
 check:
 	curl -sf http://127.0.0.1:8000/state/health | python3 -m json.tool
 
+test:
+	TEST_DATABASE_URL=postgresql+asyncpg://custodian:changeme@127.0.0.1:5432/custodian_test \
+	uv run pytest -x -q
+
 ## COULOMBCORE host (default target for tunnel targets)
 COULOMBCORE ?= tegwick@92.205.130.254
 TUNNEL_PORT ?= 8000