feat: initial qobuz-qt source

Lightweight Qt6 desktop client for Qobuz with a Rust audio backend
(Symphonia/CPAL via staticlib FFI). Mirrors the spotify-qt layout:
toolbar with playback controls, library/context docks on the left,
tabbed search side panel on the right, queue panel, now-playing dock.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

BUILD.md

@@ -20,6 +20,30 @@ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 source "$HOME/.cargo/env"
 ```
 
+### Alpine Linux
+```bash
+sudo apk add \
+    cmake \
+    ninja \
+    qt6-qtbase-dev \
+    qt6-qtsvg-dev \
+    openssl-dev \
+    alsa-lib-dev \
+    dbus-dev \
+    pkgconf \
+    curl \
+    musl-dev \
+    gcc \
+    g++
+
+# Rust toolchain
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+source "$HOME/.cargo/env"
+```
+
+> **Note:** CPAL uses ALSA on Alpine. If you prefer PipeWire/PulseAudio,
+> install `pipewire-alsa` so ALSA routes through it automatically.
+
 ### Arch Linux
 ```bash
 sudo pacman -S cmake ninja qt6-base qt6-svg openssl alsa-lib rust