Improve auth system, performance, and infrastructure

This release focuses on authentication improvements, performance optimizations, and infrastructure updates.

🔐 Authentication

• Added flexible authentication modes with local bypass support
• Improved authentication handling
• Fixed session management issues when using subpaths

🎨 UI Improvements

• Introduced BaseCheckbox component
• Refactored checkbox usage across the application

⚡ Performance

• Increased API fetch limit to improve recent items uniqueness
• Optimized TMDB and OMDB API calls
• Improved AI search merging from O(N²) to O(N)

🐳 Infrastructure

• Updated Docker workflows
• Improved GHCR authentication handling
• Fixed Docker image publishing
• Added automatic push to GHCR (GitHub Container Registry) alongside existing Docker Hub publishing

📦 Dependencies

• Updated backend and frontend dependencies

⚙️ Configuration

• Added option to include adult content in TMDB searches (@DarkseidAM)

🧹 Misc

• General cleanup and minor fixes