Add missing Bruno requests for all API endpoints:
Library Management:
- Get Library - retrieve single library details
- Update Library - modify existing library
- Delete Library - remove library and media items
- Delete Library Folder - remove folder from library
- Get Library Stats - retrieve library statistics
Media Items Management:
- Create Media Item - add new media with full metadata
- Update Media Item - modify existing media metadata
- Delete Media Item - remove media from library
- Get Media Rating - retrieve single media rating
- Delete Media Rating - remove user's media rating
Coverage now complete: 47/47 API endpoints have Bruno requests
Organized requests in proper folder structure for maintainability