feat: recording upload and management API with tests

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

backend/app/schemas/recording.py

@@ -0,0 +1,25 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel
+
+from app.models.recording import RecordingSource, RecordingStatus
+
+
+class RecordingResponse(BaseModel):
+    id: uuid.UUID
+    user_id: uuid.UUID
+    title: str
+    file_size: int
+    duration: float | None
+    format: str
+    source: RecordingSource
+    status: RecordingStatus
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class RecordingList(BaseModel):
+    items: list[RecordingResponse]
+    total: int