Initial commit — ferrosonic terminal Subsonic client

Terminal-based Subsonic music client in Rust featuring bit-perfect audio
playback via PipeWire sample rate switching, gapless playback, MPRIS2
desktop integration, cava audio visualizer with theme-matched gradients,
13 built-in color themes with custom TOML theme support, mouse controls,
artist/album browser, playlist support, and play queue management.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/ui/pages/mod.rs

@@ -0,0 +1,7 @@
+//! UI page implementations
+
+pub mod artists;
+pub mod playlists;
+pub mod queue;
+pub mod server;
+pub mod settings;