feat(audio): add alsa-utils help modal with distro-specific install commands

- Add check_alsa_utils_installed and get_linux_distro Tauri commands
- Detect Linux distribution from /etc/os-release
- Show appropriate package manager command for each distro
- Add (?) help icon next to ALSA Direct device dropdown in Settings
- Modal explains why alsa-utils is needed for bit-perfect detection
- Updated PKGBUILDs to list alsa-utils as optdepend

packaging/arch/PKGBUILD

@@ -23,6 +23,11 @@ makedepends=(
   pkgconf
   clang
 )
+optdepends=(
+  'alsa-utils: Required for bit-perfect device detection and better ALSA device names'
+  'pipewire-alsa: PipeWire audio support'
+  'pipewire-pulse: PulseAudio compatibility'
+)
 source=("https://github.com/vicrodh/qbz/archive/refs/tags/v${pkgver}.tar.gz")
 sha256sums=('SKIP')