Screensaver Shaders and theme branding

[HowieDuhzit]

Enhance screensaver functionality and theme integration

Add hyprshade shader support and theme-based branding system for screensaver
and fastfetch. This allows each theme to have its own custom branding files
and optional shader effects that automatically apply when the screensaver
activates.

Features:

• Hyprshade integration: Screensaver can apply screen shaders from theme
  configuration with automatic state preservation and restoration
• Theme-based branding: Each theme can have its own screensaver.txt and
  about.txt files that automatically apply when switching themes
• Graceful fallback: All new features maintain backward compatibility with
  existing global branding files

Changes:

• bin/omarchy-launch-screensaver:

  • Load shader configuration from current theme's screensaver.conf
  • Support single shader or random selection from array
  • Store and restore previous shader state on screensaver exit
  • Environment variable override support (OMARCHY_SCREENSAVER_SHADER)

• bin/omarchy-cmd-screensaver:

  • Use theme-specific screensaver.txt with fallback to global branding
  • Restore previous shader state when screensaver exits
  • Clean shutdown handling for shader restoration

• bin/omarchy-menu:

  • Update "Screensaver" and "About" menu options to edit theme-specific
    branding files with automatic fallback to global files

• bin/omarchy-theme-set:

  • Automatically copy theme's branding files (about.txt, screensaver.txt)
    to global location when switching themes
  • Ensures fastfetch uses correct branding immediately after theme change

• install/config/branding.sh:

  • Theme-aware branding file setup
  • Prioritizes theme-specific files over global defaults
  • Maintains backward compatibility for existing installations

Each theme can now define:

• screensaver.conf: Optional shader configuration (single or random selection)
• screensaver.txt: Custom ASCII art for screensaver display
• about.txt: Custom ASCII art for fastfetch logo

All features degrade gracefully when hyprshade is not installed or theme
files are missing, ensuring no breaking changes for existing users.

[HowieDuhzit]

https://x.com/HowieDuhzit/status/1985307860109054446