feat: implement lazy-loading assets and 3D text engine

[0xarchit]

Description:
This major update transitions PauseCat to a lightweight, lazy-load architecture and introduces a high-fidelity 3D customization suite for the break experience.

Key Deliverables:

1. Lazy Asset Architecture:

   • Reduced MSI Size: Moved the ~2MB default.webm out of the installer. It is now fetched on first run via a robust background syncer in src/updater.rs.
   • Resilient Syncing: Implemented a 3-stage retry loop and a "Retry" UI button to handle transient network failures.
   • Real-time Progress: Added a 0-100% progress bar in the settings footer to track asset synchronization live.

2. Cinematic 3D Text Engine:

   • Volumetric Extrusion: Added physical "Heavy" 3D depth to custom break text using a dynamic multi-layered shadow engine.
   • Full 3D Orientation: Added X, Y, and Z axis rotation controls for precise text angling.
   • Neon Glow FX: Integrated a granular bloom/glow intensity slider and custom glow color picker.
   • Adaptive Coloring: Smart logic that automatically flips text between Light/Dark variants based on the system theme for maximum visibility.

3. UI/UX Refinements:

   • Proportional Live Preview: Locked the preview area to a 16:9 cinematic aspect ratio with virtual 1080p scaling, ensuring a 1:1 match with real monitor proportions.
   • Aligned Grid Layout: Overhauled the Settings UI with a professional grid system.
   • Reliable State Management: Implemented a formal "Ready" handshake between the WebView and Rust backend to eliminate hydration race conditions and "Hard Broken" UI states.

4. Content & Logic Upgrades:

   • Added professional default break messages with randomization enabled.
   • Replaced the simple mute toggle with a 0-100% volume slider for cinematic videos.
   • Restored full management for Whitelist apps and Custom Message tags.

Technical Impact:

• Drastically smaller initial download footprint.
• More robust multi-threaded asset management.
• Significantly higher visual polish and user customization options.

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[0xarchit]

changes reviewed