修复白屏BUG、UI 边界溢出 BUG

lib/features/scoring/application/score_math.dart

@@ -9,14 +9,26 @@ class ScoreMath {
   const ScoreMath._();
 
   /// Returns the score [0..10] for a hit at [normalizedX]/[normalizedY].
+  ///
+  /// Uses standard FITA ring proportions (as fraction of target radius):
+  ///   Ring 10:  0 - 5%
+  ///   Ring 9:   5% - 15%
+  ///   Ring 8:  15% - 25%
+  ///   ...
+  ///   Ring 1:  85% - 100%
+  ///   Miss:    > 100%
   static int scoreFor(double normalizedX, double normalizedY) {
     final d = distance(normalizedX, normalizedY);
-    if (d > 1.0) return 0; // miss
-    final ring = (d * 10).floor();
-    var score = 10 - ring;
-    if (score < 1) score = 1;
-    if (score > 10) score = 10;
-    return score;
+    if (d > 1.0) return 0;
+
+    if (d <= 0.05) return 10;
+
+    final k = ((d - 0.05) / 0.1).floor();
+    final ring = 9 - k;
+
+    if (ring < 1) return 1;
+    if (ring > 9) return 9;
+    return ring;
   }
 
   /// Euclidean distance from center for normalized coords.