fix: 输入校验忽略多个连续空格与大小写；统一中英文引号与空白规范化

kouyu_english/test/dialogue_task_test.dart

@@ -84,6 +84,25 @@ void main() {
       expect(dialogueTaskLabel(a0MeetDialogue, 9), '完成本轮任务');
     });
 
+    test('输入校验忽略多余空格与大小写', () {
+      expect(
+        matchesDialogueStage(a0MeetDialogue, 0, "   MY    NAME    IS    SHEN   "),
+        isTrue,
+      );
+      expect(
+        matchesDialogueStage(a0Dialogues["a0-02"]!, 1, "  S   H   E   N  "),
+        isTrue,
+      );
+      expect(
+        matchesDialogueStage(a0Dialogues["a0-04"]!, 0, "MY   NUMBER   IS   ONE-THREE-EIGHT"),
+        isTrue,
+      );
+      expect(
+        matchesDialogueStage(a0Dialogues["a0-08"]!, 2, "IT'S    THREE    O'CLOCK"),
+        isTrue,
+      );
+    });
+
     test('给 AI 的可用词表随课程递增且不越界', () {
       final first = taughtLanguageUpTo('a0-01');
       final later = taughtLanguageUpTo('a0-09');