Rust Engine API and Worker

Overview

HTTP API (warp) under /api for file management and query lifecycle
MySQL for metadata, Qdrant for vector similarity
Background worker resumes queued work and re-queues stale InProgress jobs at startup

POST /api/files (multipart)
- Form: file=@path
- Response: {"success": true}
GET /api/files/list
- Response: {"files": [{"id","filename","path","description"}]}
GET /api/files/delete?id=<file_id>
- Response: {"deleted": true|false}
POST /api/query/create
- Body: {"q": "text", "top_k": 5}
- Response: {"id": "uuid"}
GET /api/query/status?id=<query_id>
- Response: {"status": "Queued"|"InProgress"|"Completed"|"Cancelled"|"Failed"|"not_found"}
GET /api/query/result?id=<query_id>
- Response (Completed): { "result": { "summary": "Found N related files", "related_files": [ {"id","filename","path","description","score"} ], "relationships": "...", "final_answer": "..." } }
GET /api/query/cancel?id=<query_id>
- Response: {"cancelled": true}