feat: staggered star reveal and near-miss progress ring

Stars on win now appear sequentially with elastic-bounce via
TweenAnimationBuilder (400/650/900 ms). Lost overlay shows a
CircularProgressIndicator ring with "87% complete!" (l10n:
almostThere) when objectiveProgress > 0.

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

lib/l10n/app_en.arb

@@ -20,5 +20,13 @@
         "type": "int"
       }
     }
+  },
+  "almostThere": "{percent}% complete!",
+  "@almostThere": {
+    "placeholders": {
+      "percent": {
+        "type": "int"
+      }
+    }
   }
 }

lib/l10n/app_ko.arb

@@ -13,5 +13,6 @@
   "giveUp": "포기하기",
   "playAgain": "다시 하기",
   "nextStage": "다음 스테이지",
-  "streakMilestone": "{days}일 연속 플레이! 대단해요!"
+  "streakMilestone": "{days}일 연속 플레이! 대단해요!",
+  "almostThere": "{percent}% 달성!"
 }

lib/ui/screens/game_screen.dart

@@ -344,16 +344,46 @@ class _GameScreenState extends ConsumerState<GameScreen>
                       mainAxisSize: MainAxisSize.min,
                       children: [
                         for (var i = 0; i < 3; i++)
-                          Icon(
-                            Icons.star,
-                            size: 40,
-                            color: i < view.starsEarned
-                                ? Colors.amber
-                                : Colors.white24,
+                          TweenAnimationBuilder<double>(
+                            tween: Tween(begin: 0, end: 1),
+                            duration: Duration(milliseconds: 400 + i * 250),
+                            curve: Interval(i * 0.22, 1, curve: Curves.elasticOut),
+                            builder: (context, v, child) =>
+                                Transform.scale(scale: v, child: child),
+                            child: Icon(
+                              Icons.star,
+                              size: 44,
+                              color: i < view.starsEarned ? Colors.amber : Colors.white24,
+                            ),
                           ),
                       ],
                     ),
                   ],
+                  if (view.phase == GamePhase.lost && view.objectiveProgress > 0) ...[
+                    const SizedBox(height: 16),
+                    SizedBox(
+                      width: 88,
+                      height: 88,
+                      child: Stack(
+                        fit: StackFit.expand,
+                        children: [
+                          CircularProgressIndicator(
+                            value: view.objectiveProgress,
+                            strokeWidth: 7,
+                            backgroundColor: Colors.white12,
+                            color: Colors.amber,
+                          ),
+                          Center(
+                            child: Text(
+                              l10n.almostThere((view.objectiveProgress * 100).round()),
+                              textAlign: TextAlign.center,
+                              style: theme.textTheme.labelSmall,
+                            ),
+                          ),
+                        ],
+                      ),
+                    ),
+                  ],
                   const SizedBox(height: 20),
                   ...actions,
                 ],