feat: add pose and appearance endpoints for face detail display

- Add GET /api/v1/file/:file_uuid/pose endpoint
- Add GET /api/v1/file/:file_uuid/appearance endpoint
- Keypoint deduplication (highest confidence)
- Add face-groups endpoint for Studio integration
- Add profile routes (trace-profile, file-profile)
- Update API documentation

src/api/mod.rs

@@ -14,6 +14,7 @@ pub mod media_api;
 pub mod middleware;
 pub mod pipeline;
 pub mod processing;
+pub mod profile;
 pub mod scan;
 pub mod search;
 pub mod server;