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

requirements.txt

@@ -7,3 +7,4 @@ beautifulsoup4==4.12.*
 Pillow==11.*
 requests==2.32.*
 pytest==8.*
+python-dotenv==1.0.*