feat: juice kit - sparks, score popups, combo banners, confetti, haptics, shake

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/ui/widgets/board_widget.dart

@@ -24,7 +24,6 @@ class _BoardWidgetState extends State<BoardWidget>
 
   List<int> _flashRows = const [];
   List<int> _flashCols = const [];
-  int _comboStreak = 0;
 
   @override
   void didUpdateWidget(BoardWidget old) {
@@ -35,7 +34,6 @@ class _BoardWidgetState extends State<BoardWidget>
         placement.linesCleared > 0) {
       _flashRows = placement.clearedRows;
       _flashCols = placement.clearedCols;
-      _comboStreak = placement.comboStreak;
       _flash.forward(from: 0);
     }
   }
@@ -66,26 +64,6 @@ class _BoardWidgetState extends State<BoardWidget>
                   flashCols: _flashCols,
                 ),
               ),
-              if (_flash.isAnimating && _comboStreak >= 2)
-                Center(
-                  child: Transform.scale(
-                    scale: 0.8 + 0.6 * _flash.value,
-                    child: Opacity(
-                      opacity: 1 - _flash.value,
-                      child: Text(
-                        'COMBO x$_comboStreak',
-                        style: TextStyle(
-                          fontSize: 36,
-                          fontWeight: FontWeight.w900,
-                          color: Colors.amber.shade300,
-                          shadows: const [
-                            Shadow(blurRadius: 12, color: Colors.black54),
-                          ],
-                        ),
-                      ),
-                    ),
-                  ),
-                ),
             ],
           );
         },