feat: surgery pipeline API, video inference, voice confirm, and tests

- Add FastAPI routes for surgery start/end, results, pending confirmation (WAV upload), and health checks.
- Implement RTSP/Hikvision capture, consumable classification, session manager, MinIO/Baidu voice resolution, and DB persistence.
- Add documentation (client API, video backends, staging checklist) and sample camera/RTSP config.
- Add pytest suite (API contract, session manager, voice, repositories, pipeline persistence) and httpx dev dependency.
- Replace deprecated HTTP_422_UNPROCESSABLE_ENTITY with HTTP_422_UNPROCESSABLE_CONTENT.
- Fix SurgeryPipeline DB reads to use an explicit transaction with autobegin disabled.

Made-with: Cursor

app/surgery_errors.py

@@ -0,0 +1,10 @@
+"""Errors surfaced by the surgery recording / result pipeline."""
+
+
+class SurgeryPipelineError(Exception):
+    """录制未能按约定完成启动或停止。"""
+
+    def __init__(self, code: str, message: str) -> None:
+        self.code = code
+        self.message = message
+        super().__init__(message)