CI / gate (push) Has been cancelled
Real bug:
- capability_registry.resolve_auto_model and chat_media._build_media_route used
`Column.op("JSON_CONTAINS")(col, val)`, but SQLAlchemy's op() accepts only ONE
argument -> TypeError on every image/video/audio auto-route, silently failing
media generation (caught as "后台生成异常"). Replaced with func.json_contains().
Test reconciliation (no production behavior change):
- tests/test_context_engine.py: tiktoken upgrade made the hardcoded len//2 token
estimates wrong; relax to tokenizer-agnostic assertions and add
structured_memory=None to the _Summary mock (code now branches on it).
- tests/test_regression_r1r2r3.py: R3 FakeModel lacked `name` (code reads m.name);
also the assertion assumed a literal '超时' string, but the failover architecture
catches model-level exceptions and writes a user-understandable error marker
instead. Align the assertion to the real contract: a media failure/timeout must
be written back as a user-understandable error message, never left as '生成中…'.
CI gate: 28 backend pytest + 15 frontend vitest all green.