Add display_format config, fix restart command, clean up config code

- Add display_format option with get/set/list/unset for customizing track display
- Add Track::format() supporting $ARTIST, $ALBUM, $TRACK variables
- Update queue, status, notifications to use display_format
- Fix restart command using wrong subcommand 'start' -> 'start-daemon'
- Remove socket_path from config (now computed at runtime from XDG_RUNTIME_DIR)
- Consolidate duplicate save() and save_all() into single save()
- Fix redundant .clone().clone() in config.rs
- Add todo item for caching config in daemon hot paths

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/queue.rs b/tests/queue.rs
index 438fa23..a73c312 100644
--- a/tests/queue.rs
+++ b/tests/queue.rs
@@ -248,6 +248,32 @@ fn test_track_display_index_offset() {
     assert_eq!(t.display_string(4, 10), "05. Artist - Title");
 }
 
+#[test]
+fn test_track_format_variables() {
+    let t = track(
+        "/music/test.mp3",
+        Some("My Song"),
+        Some("John Doe"),
+        Some("Great Album"),
+    );
+    assert_eq!(t.format("$ARTIST - $TRACK"), "John Doe - My Song");
+    assert_eq!(t.format("$TRACK ($ALBUM)"), "My Song (Great Album)");
+    assert_eq!(t.format("Now playing: $ARTIST"), "Now playing: John Doe");
+}
+
+#[test]
+fn test_track_format_empty_variables() {
+    let t = track_no_meta("/music/test.mp3");
+    assert_eq!(t.format("$ARTIST - $TRACK"), " - test.mp3");
+}
+
+#[test]
+fn test_track_format_missing_variables() {
+    let t = track("/music/test.mp3", Some("My Song"), Some("John Doe"), None);
+    assert_eq!(t.format("Track: $TRACK"), "Track: My Song");
+    assert_eq!(t.format("Album: $ALBUM"), "Album: ");
+}
+
 // ---------- Shuffle ----------
 
 #[test]