feat(juice): button press feedback + fade screen transitions

Adds PressableScale (0.94 squish on tap-down) around the Adventure
FilledButton, Classic OutlinedButton, and each season-map stage node.
Replaces all in-app MaterialPageRoute pushes with a gentle fade+scale
PageRouteBuilder (320ms in, 240ms out) via a new fadeRoute helper.

lib/ui/screens/home_screen.dart

@@ -6,6 +6,8 @@ import '../../game/models/stage.dart';
 import '../../l10n/gen/app_localizations.dart';
 import '../../state/providers.dart';
 import '../widgets/banner_ad_slot.dart';
+import '../widgets/fade_route.dart';
+import '../widgets/pressable_scale.dart';
 import '../widgets/season_background.dart';
 import 'game_screen.dart';
 import 'season_map_screen.dart';
@@ -67,7 +69,8 @@ class HomeScreen extends ConsumerWidget {
                               ),
                             ],
                             const SizedBox(height: 44),
-                            FilledButton(
+                            PressableScale(
+                              child: FilledButton(
                                 style: FilledButton.styleFrom(
                                   padding: const EdgeInsets.symmetric(
                                       horizontal: 56, vertical: 18),
@@ -76,14 +79,15 @@ class HomeScreen extends ConsumerWidget {
                                 onPressed: () {
                                   if (!(ModalRoute.of(context)?.isCurrent ?? true)) return;
                                   Navigator.of(context).push(
-                                  MaterialPageRoute(
-                                      builder: (_) => const SeasonMapScreen()),
+                                    fadeRoute(const SeasonMapScreen()),
                                   );
                                 },
                                 child: Text(l10n.adventure),
                               ),
+                            ),
                             const SizedBox(height: 14),
-                            OutlinedButton(
+                            PressableScale(
+                              child: OutlinedButton(
                                 style: OutlinedButton.styleFrom(
                                   padding: const EdgeInsets.symmetric(
                                       horizontal: 40, vertical: 14),
@@ -99,12 +103,12 @@ class HomeScreen extends ConsumerWidget {
                                         ),
                                       );
                                   Navigator.of(context).push(
-                                  MaterialPageRoute(
-                                      builder: (_) => const GameScreen()),
+                                    fadeRoute(const GameScreen()),
                                   );
                                 },
                                 child: Text(l10n.classic),
                               ),
+                            ),
                             if (best > 0) ...[
                               const SizedBox(height: 10),
                               Text(
@@ -127,7 +131,7 @@ class HomeScreen extends ConsumerWidget {
                   child: IconButton(
                     icon: const Icon(Icons.settings, color: Colors.white70),
                     onPressed: () => Navigator.of(context).push(
-                      MaterialPageRoute(builder: (_) => const SettingsScreen()),
+                      fadeRoute(const SettingsScreen()),
                     ),
                   ),
                 ),

lib/ui/screens/season_map_screen.dart

@@ -5,7 +5,9 @@ import '../../game/models/season.dart';
 import '../../state/providers.dart';
 import '../theme/palette.dart';
 import '../widgets/banner_ad_slot.dart';
+import '../widgets/fade_route.dart';
 import '../widgets/map_layout.dart';
+import '../widgets/pressable_scale.dart';
 import '../widgets/season_background.dart';
 import '../widgets/tile_painter.dart';
 import 'game_screen.dart';
@@ -193,6 +195,7 @@ class _JourneyMapState extends ConsumerState<_JourneyMap> {
       key: Key('stage_node_$i'),
       left: center.dx - size / 2,
       top: center.dy - size / 2,
+      child: PressableScale(
         child: GestureDetector(
           onTap: !isUnlocked
               ? null
@@ -201,7 +204,7 @@ class _JourneyMapState extends ConsumerState<_JourneyMap> {
                       .read(seasonFlowProvider.notifier)
                       .startSeasonStage(widget.pack, i);
                   Navigator.of(context).push(
-                  MaterialPageRoute(builder: (_) => const GameScreen()),
+                    fadeRoute(const GameScreen()),
                   );
                 },
           child: Column(
@@ -268,6 +271,7 @@ class _JourneyMapState extends ConsumerState<_JourneyMap> {
             ],
           ),
         ),
+      ),
     );
   }
 }

lib/ui/widgets/fade_route.dart

@@ -0,0 +1,22 @@
+// lib/ui/widgets/fade_route.dart
+import 'package:flutter/material.dart';
+
+/// A gentle fade(+slight scale) page transition for in-app navigation.
+Route<T> fadeRoute<T>(Widget page) {
+  return PageRouteBuilder<T>(
+    transitionDuration: const Duration(milliseconds: 320),
+    reverseTransitionDuration: const Duration(milliseconds: 240),
+    pageBuilder: (_, _, _) => page,
+    transitionsBuilder: (_, animation, _, child) {
+      final curved =
+          CurvedAnimation(parent: animation, curve: Curves.easeOutCubic);
+      return FadeTransition(
+        opacity: curved,
+        child: ScaleTransition(
+          scale: Tween(begin: 0.98, end: 1.0).animate(curved),
+          child: child,
+        ),
+      );
+    },
+  );
+}

lib/ui/widgets/pressable_scale.dart

@@ -0,0 +1,37 @@
+// lib/ui/widgets/pressable_scale.dart
+import 'package:flutter/material.dart';
+
+/// Wraps a tappable child with a quick scale-down on press for tactile feel.
+/// If [onTap] is provided it handles the tap; otherwise the child's own
+/// gesture/button handles it and this only adds the visual squish.
+class PressableScale extends StatefulWidget {
+  const PressableScale({super.key, required this.child, this.onTap});
+
+  final Widget child;
+  final VoidCallback? onTap;
+
+  @override
+  State<PressableScale> createState() => _PressableScaleState();
+}
+
+class _PressableScaleState extends State<PressableScale> {
+  bool _down = false;
+  void _set(bool v) => setState(() => _down = v);
+
+  @override
+  Widget build(BuildContext context) {
+    return GestureDetector(
+      behavior: HitTestBehavior.opaque,
+      onTapDown: (_) => _set(true),
+      onTapUp: (_) => _set(false),
+      onTapCancel: () => _set(false),
+      onTap: widget.onTap,
+      child: AnimatedScale(
+        scale: _down ? 0.94 : 1.0,
+        duration: const Duration(milliseconds: 90),
+        curve: Curves.easeOut,
+        child: widget.child,
+      ),
+    );
+  }
+}