feat: mvp viode

wei_ai_app/lib/screens/interaction/interaction_screen.dart

@@ -5,6 +5,7 @@ import 'package:go_router/go_router.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../../core/core.dart';
 import 'voice_mode_overlay.dart';
+import 'voice_session_controller.dart';
 
 class InteractionScreen extends ConsumerStatefulWidget {
   final String characterId;
@@ -20,6 +21,7 @@ class _InteractionScreenState extends ConsumerState<InteractionScreen> {
   List<ChatMessage> _messages = [];
   final TextEditingController _controller = TextEditingController();
   final ScrollController _scrollController = ScrollController();
+  VoiceSessionController? _voiceController;
   bool _isVoiceMode = false;
   bool _isLoading = false;
   bool _isTyping = false;
@@ -31,8 +33,10 @@ class _InteractionScreenState extends ConsumerState<InteractionScreen> {
     _loadCharacterAndMessages();
   }
 
+  @override
   @override
   void dispose() {
+    _voiceController?.dispose();
     _controller.dispose();
     _scrollController.dispose();
     super.dispose();
@@ -81,6 +85,38 @@ class _InteractionScreenState extends ConsumerState<InteractionScreen> {
     });
   }
 
+  void _enterVoiceMode() {
+    FocusScope.of(context).unfocus();
+    _voiceController = VoiceSessionController(
+      character: _character!,
+      onUserMessage: (text) {
+        if (!mounted) return;
+        final userMsg = ChatMessage.user(text);
+        setState(() {
+          _messages = [..._messages, userMsg];
+        });
+        ChatStorageService.addMessage(widget.characterId, userMsg);
+        _scrollToBottom();
+      },
+      onAiMessage: (msg) {
+        if (!mounted) return;
+        setState(() {
+          _messages = [..._messages, msg];
+        });
+        ChatStorageService.addMessage(widget.characterId, msg);
+        _scrollToBottom();
+      },
+    );
+    
+    setState(() => _isVoiceMode = true);
+  }
+
+  void _exitVoiceMode() {
+    _voiceController?.dispose();
+    _voiceController = null;
+    setState(() => _isVoiceMode = false);
+  }
+
   Future<void> _sendMessage() async {
     if (_controller.text.trim().isEmpty || _character == null || _isLoading) return;
 
@@ -273,10 +309,11 @@ class _InteractionScreenState extends ConsumerState<InteractionScreen> {
           ),
 
 
-          if (_isVoiceMode && _character != null)
+          if (_isVoiceMode && _character != null && _voiceController != null)
             VoiceModeOverlay(
               character: _character!,
-              onClose: () => setState(() => _isVoiceMode = false),
+              controller: _voiceController!,
+              onClose: _exitVoiceMode,
             ),
         ],
       ),
@@ -405,10 +442,7 @@ class _InteractionScreenState extends ConsumerState<InteractionScreen> {
           child: Row(
             children: [
               GestureDetector(
-                onTap: () {
-                  FocusScope.of(context).unfocus();
-                  setState(() => _isVoiceMode = true);
-                },
+                onTap: _enterVoiceMode,
                 child: Container(
                   width: 44,
                   height: 44,