fix(lyrics): smooth highlight lift and keep romanization still

Ease the lift before each highlight and let it settle more gradually for held words. Keep timed pronunciation and translation lines stationary while preserving their color sweep.

lib/utils/synced_lyrics_scroll.dart

@@ -98,14 +98,14 @@ double syncedLyricSegmentLift({
     return t * t * (3 - 2 * t);
   }
 
-  // Anticipate the highlight slightly without moving the list's layout.
-  final normalLift = ease(
-    (elapsed + 100) / (100 + math.min(160, duration * 0.35)),
-  );
+  // Start gently before the color sweep and let the movement trail it. Keep
+  // this envelope independent of word length: fast syllables must not snap
+  // upwards just because their highlight finishes in a few frames.
+  final normalLift = ease((elapsed + 180) / 720);
   final heldStrength = ((duration - 1000) / 1500).clamp(0.0, 1.0);
   if (heldStrength == 0) return normalLift;
-  final rise = ease((elapsed - 200) / math.min(900, (duration - 200) * 0.5));
-  final settle = ease((duration - elapsed) / 300);
+  final rise = ease((elapsed - 400) / math.min(1200, (duration - 400) * 0.6));
+  final settle = ease((duration - elapsed) / 600);
   return normalLift + 1.3 * heldStrength * rise * settle;
 }