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/lyricResolve.h

@@ -14,6 +14,8 @@
 #include <string>
 #include <vector>
 
+#include "timeline.h"
+
 namespace lr {
 
 struct LyricLine {
@@ -38,17 +40,23 @@ LyricInfo parseLrcFile(const std::string& path);
 
 struct LyricDisplayOptions {
     int row = 0;       // 1-based terminal row; 0 = auto (last terminal row)
+    int col = 0;       // 1-based start column; 0 = column 1
+    int maxWidth = 0;  // max display columns; 0 = terminal width - 1
     bool show = true;  // false => run the timeline silently (no terminal writes)
 };
 
-// Play the lyrics on a timeline starting at t = 0. Blocks until every line has
-// been shown (or `stop` is set). Returns 0.
+// Play the lyrics against `timeline` (may be null for a local clock): the
+// current lyric line is displayed in real time as the timeline advances.
+// Blocks until the timeline passes the last line (or `stop` is set).
+// Returns 0.
 int playLyrics(const LyricInfo& lyric,
                const LyricDisplayOptions& opts = {},
+               Timeline* timeline = nullptr,
                std::atomic<bool>* stop = nullptr);
 
 int playLyricsFile(const std::string& path,
                    const LyricDisplayOptions& opts = {},
+                   Timeline* timeline = nullptr,
                    std::atomic<bool>* stop = nullptr);
 
 }  // namespace lr