feat(compact): Access database compact & repair API + CLI

- API: POST /api/compact (optional body {"files": [...]})
- CLI: python main.py compact [--db FILE]
- Local path: rename → CompactDatabase(bak→src) → delete bak (zero copy)
- UNC path: copy to local temp → compact → copy back (avoids DAO segfault)
- Uses DAO DBEngine.CompactDatabase via pywin32 COM
- new dep: pywin32>=306

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

requirements.txt

@@ -4,3 +4,4 @@ pydantic>=2.6.0
 fastapi>=0.110.0
 uvicorn[standard]>=0.27.0
 pytest>=8.0.0
+pywin32>=306