test: lift coverage 41% → 76% (+1068 tests across 36 files)

Service-level tests now exercise provider, permissions, project, journal,
messaging, work_session, metrics, kanban, extraction, learning, notification,
dashboard, llm_routing, a2a, task, repository_base, audit, db_seed,
branch_name, indexed_document, query_helpers, agent. API route tests cover
provider, journal, project, sessions, dashboard, work_session, tasks, a2a,
groups, notifications, agents, channels, messages, kanban, api_resources.
Pure-function helpers covered: handlers, deps_helpers, middleware,
middleware_docs, transcription, pr templates, agents_config, errors,
logging, journal/notification/channel/a2a access, task_lifecycle,
streaming, converters, crypto, schemas (common + websocket), events,
permissions extras.

pyproject ruff per-file-ignores extended for tests so PLR2004 (status code
magic values), PLC0415 (lazy imports), PLR0913 (fixture params), ARG001
(unused fixture deps), SIM105, and E501 don't fight test idioms.

tests/integration/test_a2a_routes.py

@@ -180,9 +180,7 @@ async def test_list_agents(a2a_route_client: dict) -> None:
 @pytest.mark.asyncio
 async def test_list_agents_filter_by_role(a2a_route_client: dict) -> None:
     client = a2a_route_client["client"]
-    response = await client.get(
-        "/api/a2a/agents?role=developer", headers=_HDR
-    )
+    response = await client.get("/api/a2a/agents?role=developer", headers=_HDR)
     assert response.status_code == 200