Fix real-time speech recognition display

1. Update UI to show actual _currentText instead of fixed 'realtime recognizing...' text
   - Use Flexible widget to handle text overflow
   - Show actual recognition text when available
   - Fallback to 'realtime recognizing...' when text is empty

2. Fix final result processing logic
   - Don't update _currentText when processing final results
   - Final results only append to text field, don't interfere with real-time display

3. Improve listening status management
   - Clear _currentText when recording stops
   - Ensure clean state transitions between recording sessions

This fixes the issue where users could only see final results without real-time feedback.

example/lib/main.dart

@@ -359,13 +359,17 @@ class _SpeechRecognitionPageState extends State<SpeechRecognitionPage> {
                   children: [
                     Icon(Icons.mic, size: 14, color: Colors.blue[600]),
                     const SizedBox(width: 4),
-                    Text(
-                      '实时识别中...',
+                    Flexible(
+                      child: Text(
+                        _currentText.isEmpty ? '实时识别中...' : _currentText,
                         style: TextStyle(
                           fontSize: 12,
                           color: Colors.blue[600],
                           fontWeight: FontWeight.w500,
                         ),
+                        overflow: TextOverflow.ellipsis,
+                        maxLines: 1,
+                      ),
                     ),
                   ],
                 ),
@@ -476,7 +480,7 @@ class _SpeechRecognitionPageState extends State<SpeechRecognitionPage> {
                 currentTextInBox += ' '; // 添加空格分隔
               }
               _textController.text = currentTextInBox + result.recognizedWords;
-              _currentText = result.recognizedWords; // 保存当前识别结果
+              // 最终结果不需要更新_currentText，因为录音已结束
             } else {
               // 实时结果：仅用于显示，不追加到文本框
               print('📱 [Example] 实时识别: ${result.recognizedWords}');
@@ -505,6 +509,8 @@ class _SpeechRecognitionPageState extends State<SpeechRecognitionPage> {
               if (_recognitionHistory.length > 10) {
                 _recognitionHistory.removeLast();
               }
+              // 清空当前文本，因为录音已结束
+              _currentText = '';
             });
           }
         } else {