UmbrielMod v0.1.0

Added

• First release: GTK4/libadwaita configuration editor for Umbriel.
• Settings pages generated from umbriel config schema --json, so every
  option of the installed Umbriel build is editable; descriptions extracted
  from Umbriel's documentation.
• Comment-preserving TOML editing, validation with umbriel config validate
  before every save, atomic writes and backups, undo/redo, raw editor.
• Outputs with drag-and-drop arrangement, keybind editor with conflict
  detection and key capture, rule editors for windows, layers, workspaces,
  scratchpads and devices.
• Community shader catalogue: install, activate, tune presets and GLSL
  constants.
• curl … | bash installer.