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/unit/models/test_transcription.py

@@ -103,8 +103,6 @@ def test_transcription_config_defaults() -> None:
 
 
 def test_transcription_config_custom() -> None:
-    cfg = TranscriptionConfig(
-        min_chars_for_extraction=10, max_buffers_per_agent=5
-    )
+    cfg = TranscriptionConfig(min_chars_for_extraction=10, max_buffers_per_agent=5)
     assert cfg.min_chars_for_extraction == 10
     assert cfg.max_buffers_per_agent == 5