feat: add Markdown rendering and phone-call voice entry to chat UI

Chat message rendering:
- MessageBubble: replace plain SelectableText with MarkdownBody for
  assistant messages, with full dark-theme stylesheet (headers, code
  blocks, tables, blockquotes, list bullets)
- StreamTextWidget: render completed messages as MarkdownBody, keep
  plain-text + blinking cursor for actively streaming messages

Voice interaction redesign:
- Remove all long-press-to-record code (~100 lines): AudioRecorder,
  SpeechEnhancer, mic pulse animation, voice indicator bar,
  SingleTickerProviderStateMixin
- Add phone-call button in AppBar (Icons.call) that navigates to the
  existing AgentCallPage for full-duplex voice conversation
- Add prominent "语音通话" entry button on empty chat state
- AgentCallPage was already fully implemented (ringing → connecting →
  active → ended, dual-direction WebSocket audio, GTCRN denoise,
  Kokoro TTS playback, waveform visualization) but previously unused

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

it0_app/lib/features/chat/presentation/pages/chat_page.dart

@@ -1,13 +1,5 @@
-import 'dart:async';
-import 'dart:typed_data';
-import 'package:dio/dio.dart' show FormData, MultipartFile;
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:record/record.dart';
-import '../../../../core/audio/noise_reducer.dart';
-import '../../../../core/audio/speech_enhancer.dart';
-import '../../../../core/config/api_endpoints.dart';
-import '../../../../core/network/dio_client.dart';
 import '../../../../core/theme/app_colors.dart';
 import '../../domain/entities/chat_message.dart';
 import '../providers/chat_providers.dart';
@@ -16,6 +8,7 @@ import '../widgets/tool_execution_card.dart';
 import '../widgets/approval_action_card.dart';
 import '../widgets/agent_thinking_indicator.dart';
 import '../widgets/stream_text_widget.dart';
+import '../../../agent_call/presentation/pages/agent_call_page.dart';
 
 // ---------------------------------------------------------------------------
 // Chat page – ConsumerStatefulWidget
@@ -28,108 +21,10 @@ class ChatPage extends ConsumerStatefulWidget {
   ConsumerState<ChatPage> createState() => _ChatPageState();
 }
 
-class _ChatPageState extends ConsumerState<ChatPage> with SingleTickerProviderStateMixin {
+class _ChatPageState extends ConsumerState<ChatPage> {
   final _messageController = TextEditingController();
   final _scrollController = ScrollController();
 
-  // -- Voice input (record + GTCRN denoise + backend STT) -------------------
-  late final AudioRecorder _recorder;
-  final SpeechEnhancer _enhancer = SpeechEnhancer();
-  bool _isListening = false;
-  bool _isTranscribing = false;
-  List<List<int>> _audioChunks = [];
-  StreamSubscription<List<int>>? _audioSubscription;
-  late AnimationController _micPulseController;
-
-  @override
-  void initState() {
-    super.initState();
-    _recorder = AudioRecorder();
-    _enhancer.init(); // load GTCRN model in background
-    _micPulseController = AnimationController(
-      vsync: this,
-      duration: const Duration(milliseconds: 800),
-    );
-  }
-
-  Future<void> _startListening() async {
-    final hasPermission = await _recorder.hasPermission();
-    if (!hasPermission || !mounted) return;
-
-    setState(() => _isListening = true);
-    _micPulseController.repeat(reverse: true);
-    _audioChunks = [];
-
-    // Stream raw PCM 16kHz mono with platform noise suppression + AGC
-    final stream = await _recorder.startStream(const RecordConfig(
-      encoder: AudioEncoder.pcm16bits,
-      sampleRate: 16000,
-      numChannels: 1,
-      noiseSuppress: true,
-      autoGain: true,
-    ));
-
-    _audioSubscription = stream.listen((data) {
-      _audioChunks.add(data);
-    });
-  }
-
-  Future<void> _stopListening({bool autoSubmit = false}) async {
-    if (!_isListening) return;
-
-    // Stop recording and stream
-    await _recorder.stop();
-    await _audioSubscription?.cancel();
-    _audioSubscription = null;
-    _micPulseController.stop();
-    _micPulseController.reset();
-
-    if (!mounted) return;
-    setState(() => _isListening = false);
-
-    if (!autoSubmit || _audioChunks.isEmpty) return;
-
-    // Transcribe via backend
-    setState(() => _isTranscribing = true);
-
-    try {
-      // Combine recorded chunks into a single PCM buffer
-      final allBytes = _audioChunks.expand((c) => c).toList();
-      final pcmData = Uint8List.fromList(allBytes);
-      _audioChunks = [];
-
-      // GTCRN ML denoise (light) + trim leading/trailing silence
-      final denoised = _enhancer.enhance(pcmData);
-      final trimmed = NoiseReducer.trimSilence(denoised);
-
-      if (trimmed.isEmpty) {
-        if (mounted) setState(() => _isTranscribing = false);
-        return;
-      }
-
-      // POST to backend /voice/transcribe
-      final dio = ref.read(dioClientProvider);
-      final formData = FormData.fromMap({
-        'audio': MultipartFile.fromBytes(trimmed, filename: 'audio.pcm'),
-      });
-      final response = await dio.post(
-        ApiEndpoints.transcribe,
-        data: formData,
-      );
-
-      final text =
-          (response.data as Map<String, dynamic>)['text'] as String? ?? '';
-      if (text.isNotEmpty && mounted) {
-        _messageController.text = text;
-        _send();
-      }
-    } catch (_) {
-      // Voice failed silently – user can still type
-    } finally {
-      if (mounted) setState(() => _isTranscribing = false);
-    }
-  }
-
   // -- Send ------------------------------------------------------------------
 
   void _send() {
@@ -152,6 +47,12 @@ class _ChatPageState extends ConsumerState<ChatPage> with SingleTickerProviderSt
     });
   }
 
+  void _openVoiceCall() {
+    Navigator.of(context).push(
+      MaterialPageRoute(builder: (_) => const AgentCallPage()),
+    );
+  }
+
   // -- Message widget dispatch -----------------------------------------------
 
   Widget _buildMessageWidget(ChatMessage message, ChatState chatState) {
@@ -295,31 +196,11 @@ class _ChatPageState extends ConsumerState<ChatPage> with SingleTickerProviderSt
               tooltip: '清空对话',
               onPressed: () => ref.read(chatProvider.notifier).clearChat(),
             ),
-          // Voice input button
+          // Voice call button
-          GestureDetector(
+          IconButton(
-            onLongPressStart: (_) => _startListening(),
+            icon: const Icon(Icons.call),
-            onLongPressEnd: (_) => _stopListening(autoSubmit: true),
+            tooltip: '语音通话',
-            child: AnimatedBuilder(
+            onPressed: _openVoiceCall,
-              animation: _micPulseController,
-              builder: (context, child) {
-                return IconButton(
-                  icon: Icon(
-                    _isListening ? Icons.mic : Icons.mic_none,
-                    color: _isListening
-                        ? Color.lerp(AppColors.error, AppColors.warning, _micPulseController.value)
-                        : null,
-                    size: _isListening ? 28 + (_micPulseController.value * 4) : 24,
-                  ),
-                  onPressed: () {
-                    if (_isListening) {
-                      _stopListening(autoSubmit: true);
-                    } else {
-                      _startListening();
-                    }
-                  },
-                );
-              },
-            ),
           ),
         ],
       ),
@@ -358,9 +239,20 @@ class _ChatPageState extends ConsumerState<ChatPage> with SingleTickerProviderSt
                         ),
                         const SizedBox(height: 8),
                         Text(
-                          '长按麦克风按钮进行语音输入',
+                          '输入文字或拨打语音通话',
                           style: TextStyle(color: AppColors.textMuted, fontSize: 13),
                         ),
+                        const SizedBox(height: 24),
+                        OutlinedButton.icon(
+                          onPressed: _openVoiceCall,
+                          icon: const Icon(Icons.call),
+                          label: const Text('语音通话'),
+                          style: OutlinedButton.styleFrom(
+                            foregroundColor: AppColors.success,
+                            side: const BorderSide(color: AppColors.success),
+                            padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
+                          ),
+                        ),
                       ],
                     ),
                   )
@@ -382,46 +274,6 @@ class _ChatPageState extends ConsumerState<ChatPage> with SingleTickerProviderSt
                   ),
           ),
 
-          // Voice listening / transcribing indicator
-          if (_isListening || _isTranscribing)
-            Container(
-              padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 16),
-              color: (_isListening ? AppColors.error : AppColors.primary)
-                  .withOpacity(0.1),
-              child: Row(
-                children: [
-                  if (_isListening)
-                    AnimatedBuilder(
-                      animation: _micPulseController,
-                      builder: (context, _) => Icon(
-                        Icons.mic,
-                        color: AppColors.error,
-                        size: 20 + (_micPulseController.value * 4),
-                      ),
-                    )
-                  else
-                    const SizedBox(
-                      width: 20,
-                      height: 20,
-                      child: CircularProgressIndicator(strokeWidth: 2),
-                    ),
-                  const SizedBox(width: 8),
-                  Text(
-                    _isListening ? '正在聆听...' : '正在转写...',
-                    style: TextStyle(
-                      color: _isListening ? AppColors.error : AppColors.primary,
-                    ),
-                  ),
-                  const Spacer(),
-                  if (_isListening)
-                    TextButton(
-                      onPressed: () => _stopListening(),
-                      child: const Text('取消'),
-                    ),
-                ],
-              ),
-            ),
-
           // Input row
           _buildInputArea(chatState),
         ],
@@ -491,10 +343,6 @@ class _ChatPageState extends ConsumerState<ChatPage> with SingleTickerProviderSt
   void dispose() {
     _messageController.dispose();
     _scrollController.dispose();
-    _micPulseController.dispose();
-    _audioSubscription?.cancel();
-    _recorder.dispose();
-    _enhancer.dispose();
     super.dispose();
   }
 }

it0_app/lib/features/chat/presentation/widgets/message_bubble.dart

@@ -1,9 +1,10 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_markdown/flutter_markdown.dart';
 import '../../../../core/theme/app_colors.dart';
 import '../../domain/entities/chat_message.dart';
 
 /// Renders a single chat message bubble with appropriate styling
-/// for user and assistant messages.
+/// for user and assistant messages. Assistant messages render Markdown.
 class MessageBubble extends StatelessWidget {
   final ChatMessage message;
 
@@ -47,13 +48,20 @@ class MessageBubble extends StatelessWidget {
                 ),
               ),
 
-            // Message content
+            // Message content — Markdown for assistant, plain text for user
+            if (_isUser)
               SelectableText(
                 message.content,
-              style: TextStyle(
+                style: const TextStyle(
-                color: _isUser ? Colors.white : AppColors.textPrimary,
+                  color: Colors.white,
                   fontSize: 15,
                 ),
+              )
+            else
+              MarkdownBody(
+                data: message.content,
+                selectable: true,
+                styleSheet: _markdownStyleSheet(context),
               ),
 
             // Timestamp
@@ -75,6 +83,37 @@ class MessageBubble extends StatelessWidget {
     );
   }
 
+  MarkdownStyleSheet _markdownStyleSheet(BuildContext context) {
+    return MarkdownStyleSheet(
+      p: const TextStyle(color: AppColors.textPrimary, fontSize: 15),
+      h1: const TextStyle(color: AppColors.textPrimary, fontSize: 22, fontWeight: FontWeight.bold),
+      h2: const TextStyle(color: AppColors.textPrimary, fontSize: 19, fontWeight: FontWeight.bold),
+      h3: const TextStyle(color: AppColors.textPrimary, fontSize: 17, fontWeight: FontWeight.w600),
+      strong: const TextStyle(color: AppColors.textPrimary, fontWeight: FontWeight.bold),
+      em: const TextStyle(color: AppColors.textSecondary, fontStyle: FontStyle.italic),
+      code: TextStyle(
+        color: AppColors.secondary,
+        backgroundColor: AppColors.background.withOpacity(0.5),
+        fontSize: 13,
+        fontFamily: 'monospace',
+      ),
+      codeblockDecoration: BoxDecoration(
+        color: AppColors.background.withOpacity(0.6),
+        borderRadius: BorderRadius.circular(8),
+      ),
+      codeblockPadding: const EdgeInsets.all(10),
+      blockquoteDecoration: BoxDecoration(
+        border: Border(left: BorderSide(color: AppColors.primary, width: 3)),
+      ),
+      blockquotePadding: const EdgeInsets.only(left: 12, top: 4, bottom: 4),
+      tableBorder: TableBorder.all(color: AppColors.surfaceLight, width: 0.5),
+      tableHead: const TextStyle(color: AppColors.textPrimary, fontWeight: FontWeight.bold, fontSize: 13),
+      tableBody: const TextStyle(color: AppColors.textSecondary, fontSize: 13),
+      tableCellsPadding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+      listBullet: const TextStyle(color: AppColors.textSecondary, fontSize: 15),
+    );
+  }
+
   String _formatTime(DateTime time) {
     final hour = time.hour.toString().padLeft(2, '0');
     final minute = time.minute.toString().padLeft(2, '0');

it0_app/lib/features/chat/presentation/widgets/stream_text_widget.dart

@@ -1,8 +1,10 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_markdown/flutter_markdown.dart';
 import '../../../../core/theme/app_colors.dart';
 
 /// Widget that renders streaming text with an animated cursor at the end,
 /// giving the appearance of real-time text generation.
+/// When streaming completes, renders Markdown.
 class StreamTextWidget extends StatefulWidget {
   final String text;
   final bool isStreaming;
@@ -46,13 +48,38 @@ class _StreamTextWidgetState extends State<StreamTextWidget>
     );
     final effectiveStyle = widget.style ?? defaultStyle;
 
+    // Streaming complete — render full Markdown
     if (!widget.isStreaming) {
-      return SelectableText(
+      return MarkdownBody(
-        widget.text,
+        data: widget.text,
-        style: effectiveStyle,
+        selectable: true,
+        styleSheet: MarkdownStyleSheet(
+          p: effectiveStyle,
+          h1: effectiveStyle.copyWith(fontSize: 22, fontWeight: FontWeight.bold),
+          h2: effectiveStyle.copyWith(fontSize: 19, fontWeight: FontWeight.bold),
+          h3: effectiveStyle.copyWith(fontSize: 17, fontWeight: FontWeight.w600),
+          strong: effectiveStyle.copyWith(fontWeight: FontWeight.bold),
+          em: effectiveStyle.copyWith(fontStyle: FontStyle.italic, color: AppColors.textSecondary),
+          code: TextStyle(
+            color: AppColors.secondary,
+            backgroundColor: AppColors.background.withOpacity(0.5),
+            fontSize: 13,
+            fontFamily: 'monospace',
+          ),
+          codeblockDecoration: BoxDecoration(
+            color: AppColors.background.withOpacity(0.6),
+            borderRadius: BorderRadius.circular(8),
+          ),
+          codeblockPadding: const EdgeInsets.all(10),
+          tableBorder: TableBorder.all(color: AppColors.surfaceLight, width: 0.5),
+          tableHead: effectiveStyle.copyWith(fontWeight: FontWeight.bold, fontSize: 13),
+          tableBody: TextStyle(color: AppColors.textSecondary, fontSize: 13),
+          tableCellsPadding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+        ),
       );
     }
 
+    // Still streaming — show plain text with blinking cursor
     return AnimatedBuilder(
       animation: _cursorController,
       builder: (context, _) {