🎨 QuickPreview & UI Refinements

• 💎 Dynamic Glassmorphism: Implemented a responsive backdrop-blur and transparency system for QuickPreview controls. Floating elements now remain ultra-translucent by default and shift to a dark blurred state on hover, prioritizing media visibility.
• 🚀 "Open With" Integration: Added a native "Open With" button to the QuickPreview header, allowing instant file launching in external applications without leaving the viewer.
• ✨ Themed Context Shadows: Restored accented depth to context menus using the system's --accent-glow variable, providing both better separation from the background and a premium aesthetic.
• 🎯 Enhanced Selection Visibility: Optimized the selection state with a 15% opacity background and a 25% opacity ring border, making multi-selection significantly clearer across all views (Grid, List, Sidebar).
• 🖱ï¸� Tab Navigation Polish: Fixed a usability issue where tabs with short names were difficult to target. Set a standardized 140px minimum width for all tabs while maintaining the smooth pop-layout animations.