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.

packaging/PKGBUILD

@@ -5,7 +5,7 @@ pkgver=0.1.0
 pkgrel=1
 pkgdesc="System settings app for Bread OS"
 arch=('x86_64')
-url="https://github.com/Breadway/bos"
+url="https://github.com/Breadway/bos-settings"
 license=('MIT')
 # Some Rust deps (ring/mlua) build vendored C/asm into static archives; makepkg's
 # default -flto=auto emits GCC LTO bitcode the Rust (lld) link cannot read,
@@ -21,18 +21,18 @@ sha256sums=('SKIP')
 
 build() {
   cd "${srcdir}/${pkgname}-${pkgver}"
-  cargo build --release --locked -p bos-settings
+  cargo build --release --locked
 }
 
 check() {
   cd "${srcdir}/${pkgname}-${pkgver}"
-  cargo test --release --locked -p bos-settings
+  cargo test --release --locked
 }
 
 package() {
   cd "${srcdir}/${pkgname}-${pkgver}"
   install -Dm755 target/release/bos-settings "${pkgdir}/usr/bin/bos-settings"
-  install -Dm644 packaging/arch/bos-settings.desktop \
+  install -Dm644 packaging/bos-settings.desktop \
     "${pkgdir}/usr/share/applications/bos-settings.desktop"
   install -Dm644 LICENSE "${pkgdir}/usr/share/licenses/${pkgname}/LICENSE"
 }