Extract bos-settings into its own repo; add Appearance/Startup Apps/Display editors

Split out of the bos repo so a bos-settings release no longer requires a
BOS ISO release (and vice versa) — CI here publishes straight to the
[breadway] pacman repo on tag push, independent of bos's own release cadence.

Also adds real GUI editors for the Hyprland JSON config surfaces bos gained
recently (hypr/settings.json, hypr/monitors.json, hypr/autostart.json):
- Appearance panel: gaps, borders (with a real color picker), blur, shadow,
  tiling layout, and basic input settings.
- Display panel: a monitor-rule list editor alongside the existing live
  connected-monitor readout.
- Startup Apps panel: toggle/edit/add/remove the extra autostart commands.
- --page argv support for deep-linking (breadhelp's guides can now open
  bos-settings straight to a specific page).
- Fixed a stale "View keybinds cheat sheet" button pointing at a file
  deleted when breadhelp replaced bos-keybinds/bos-welcome.

.gitignore

@@ -0,0 +1,34 @@
+# Rust build artifacts
+/target/
+**/*.pdb
+
+# Editor / IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+.direnv/
+
+# OS artifacts
+.DS_Store
+Thumbs.db
+desktop.ini
+
+# Environment / secrets
+.env
+.env.local
+*.env.*
+secrets/
+*.pem
+*.key
+*.p12
+
+# Runtime / logs
+*.log
+logs/
+*.pid
+*.sock
+
+# Claude Code local agent state
+.claude/