feat: add Grimmory/Booklore push integration

- Added "Push to Library" button to issues archive
- Implemented direct API upload to Grimmory/Booklore
- Added support for `.env` files via `python-dotenv`
- Handled 409 Conflict for duplicate files gracefully
- Resolved library name to numeric ID for direct uploads
- Fixed SQLAlchemy and ebooklib warnings in tests
- Added comprehensive tests for push functionality

Made-with: Cursor

.gitignore

@@ -2,6 +2,7 @@ data/
 __pycache__/
 *.pyc
 .venv/
+.env
 *.egg-info/
 dist/
 build/