v0.3.1 - Loading Interstitial for Page Navigation

New Features

Loading Interstitial Overlay

• Page transition overlay - Displays a loading spinner with blur backdrop during page navigation
• Improved perceived performance - Users see immediate feedback when clicking navigation links
• Smooth transitions - Loading state automatically clears when page content is ready

Implementation Details

State Management

• Added is_page_loading state to AppState for centralized loading control
• set_page_loading() method for programmatic state changes

Navigation Integration

• Navbar links trigger loading overlay via on_click handler
• All page on_load handlers reset loading state when content loads

Visual Design

• Centered spinner with "Loading..." text
• Semi-transparent dark backdrop with blur effect
• Positioned to cover main content area (accounts for navbar width)

Files Changed

• src/plexmix/ui/states/app_state.py - Added loading state management
• src/plexmix/ui/components/navbar.py - Added overlay component and layout integration
• src/plexmix/ui/states/*.py - All page states clear loading on load

Testing

All 116 tests passing ✅