feat: make everything threads-safe.

feat: complete `uninstall.sh` logic to make everything synced.
	feat: complete basic play logic to handle background, music,
	lyric play.

modules/musicPlayer.cpp

@@ -73,9 +73,13 @@ void dataCallback(ma_device* device, void* out, const void* /*in*/,
 
 }  // namespace
 
-int play(const std::string& path, std::atomic<bool>* stop) {
+int play(const std::string& path, Timeline* timeline, std::atomic<bool>* stop) {
     if (path.empty()) return 1;
 
+    // Audio is the show's clock: anchor the timeline the moment playback is
+    // about to begin (a no-op if the caller already anchored it).
+    if (timeline && !timeline->started()) timeline->start();
+
     ma_decoder_config decoderConfig = ma_decoder_config_init_default();
     ma_decoder decoder;
     if (ma_decoder_init_file(path.c_str(), &decoderConfig, &decoder) != MA_SUCCESS) {