Add alsa-utils to all package formats with appropriate handling

AUR (Arch Linux):
- Added to optdepends: 'alsa-utils: Better ALSA device names and descriptions'
- Users get notification to install, but not required

Flatpak:
- Included alsa-utils module in bundle (builds from source)
- Version 1.2.12 from alsa-project.org
- Sandboxed environment can now execute aplay -L internally
- Disabled alsamixer and xmlto (not needed, reduces size)
- Users get real device descriptions automatically

Snap (future - not yet implemented):
- Created snapcraft.yaml template
- stage-packages includes alsa-utils
- Will be bundled when Snap support is implemented

AppImage (future - not yet implemented):
- Created README.md documenting dependencies
- AppImage uses host system commands (aplay from host)
- Users need to install alsa-utils on their system
- Fallback to CPAL works if not installed

Summary by format:
- .deb/.rpm: Recommends alsa-utils (auto-installed, can be removed)
- AUR: optdepends (user notified, optional)
- Flatpak: Bundled (always available)
- Snap: Will be bundled (future)
- AppImage: Host dependency (user installs)

packaging/aur/PKGBUILD

@@ -8,6 +8,7 @@ url="https://github.com/vicrodh/qbz"
 license=('MIT')
 depends=('webkit2gtk-4.1' 'gtk3' 'alsa-lib' 'libappindicator-gtk3' 'libxkbcommon' 'openssl')
 optdepends=(
+    'alsa-utils: Better ALSA device names and descriptions'
     'pipewire-alsa: PipeWire audio support'
     'pipewire-pulse: PulseAudio compatibility'
 )