feat: streaming claude-api engine, engineType override, fix voice test page

- Claude API engine now uses streaming API (messages.stream) for real-time
  text delta output instead of waiting for full response
- Agent controller accepts optional engineType body parameter to allow
  callers (e.g. voice pipeline) to select a specific engine
- Fix voice_test_page.dart compilation error: replace audioplayers (not
  installed) with flutter_sound (already in pubspec.yaml)

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

it0_app/lib/features/agent_call/presentation/pages/voice_test_page.dart

@@ -4,7 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:dio/dio.dart';
 import 'package:record/record.dart';
-import 'package:audioplayers/audioplayers.dart';
+import 'package:flutter_sound/flutter_sound.dart';
 import '../../../../core/network/dio_client.dart';
 
 /// Temporary voice I/O test page — TTS + STT + Round-trip.
@@ -19,8 +19,9 @@ class _VoiceTestPageState extends ConsumerState<VoiceTestPage> {
   final _ttsController = TextEditingController(
     text: '你好，我是IT0运维助手。很高兴为您服务！',
   );
-  final _audioPlayer = AudioPlayer();
+  final _audioPlayer = FlutterSoundPlayer();
   final _recorder = AudioRecorder();
+  bool _playerInitialized = false;
 
   String _ttsStatus = '';
   String _sttStatus = '';
@@ -46,10 +47,21 @@ class _VoiceTestPageState extends ConsumerState<VoiceTestPage> {
   /// Dio for JSON responses (STT).
   Dio get _dioJson => ref.read(dioClientProvider);
 
+  @override
+  void initState() {
+    super.initState();
+    _initPlayer();
+  }
+
+  Future<void> _initPlayer() async {
+    await _audioPlayer.openPlayer();
+    _playerInitialized = true;
+  }
+
   @override
   void dispose() {
     _ttsController.dispose();
-    _audioPlayer.dispose();
+    if (_playerInitialized) _audioPlayer.closePlayer();
     _recorder.dispose();
     super.dispose();
   }
@@ -73,7 +85,7 @@ class _VoiceTestPageState extends ConsumerState<VoiceTestPage> {
       setState(() {
         _ttsStatus = '完成！耗时 ${sw.elapsedMilliseconds}ms，大小 ${(bytes.length / 1024).toStringAsFixed(1)}KB';
       });
-      await _audioPlayer.play(BytesSource(Uint8List.fromList(bytes)));
+      await _playWavBytes(Uint8List.fromList(bytes));
     } catch (e) {
       sw.stop();
       setState(() => _ttsStatus = '错误: $e');
@@ -191,7 +203,7 @@ class _VoiceTestPageState extends ConsumerState<VoiceTestPage> {
         _rtResult += '\nTTS (${ttsSw.elapsedMilliseconds}ms): ${(audioBytes.length / 1024).toStringAsFixed(1)}KB';
         _rtStatus = '完成！STT=${sttSw.elapsedMilliseconds}ms + TTS=${ttsSw.elapsedMilliseconds}ms = ${totalSw.elapsedMilliseconds}ms';
       });
-      await _audioPlayer.play(BytesSource(Uint8List.fromList(audioBytes)));
+      await _playWavBytes(Uint8List.fromList(audioBytes));
     } catch (e) {
       totalSw.stop();
       setState(() {
@@ -200,6 +212,16 @@ class _VoiceTestPageState extends ConsumerState<VoiceTestPage> {
     }
   }
 
+  /// Play WAV bytes through flutter_sound player.
+  Future<void> _playWavBytes(Uint8List wavBytes) async {
+    if (!_playerInitialized) return;
+    await _audioPlayer.startPlayer(
+      fromDataBuffer: wavBytes,
+      codec: Codec.pcm16WAV,
+      whenFinished: () {},
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

packages/services/agent-service/src/infrastructure/engines/claude-api/claude-api-engine.ts

@@ -95,31 +95,52 @@ export class ClaudeApiEngine implements AgentEnginePort {
           requestParams.tools = tools;
         }
 
-        const response = await client.messages.create(requestParams, {
+        // Use streaming API for token-level output
+        const stream = client.messages.stream(requestParams, {
           signal: abortController.signal as any,
         });
 
+        const contentBlocks: AnthropicContentBlock[] = [];
+        const toolUseBlocks: Array<{ id: string; name: string; input: Record<string, unknown> }> = [];
+
+        // Stream text deltas in real-time
+        for await (const event of stream) {
+          if (event.type === 'content_block_delta') {
+            const delta = (event as any).delta;
+            if (delta?.type === 'text_delta' && delta.text) {
+              yield { type: 'text' as const, content: delta.text };
+            } else if (delta?.type === 'thinking_delta' && delta.thinking) {
+              yield { type: 'thinking' as const, content: delta.thinking };
+            }
+          } else if (event.type === 'content_block_start') {
+            const block = (event as any).content_block;
+            if (block?.type === 'tool_use') {
+              contentBlocks.push(block);
+            }
+          } else if (event.type === 'content_block_stop') {
+            // Tool use blocks are fully accumulated at stop
+          }
+        }
+
+        // Get final message for tool use and usage
+        const response = await stream.finalMessage();
+
         // Track token usage
         if (response.usage) {
           totalTokensUsed += (response.usage.input_tokens ?? 0) + (response.usage.output_tokens ?? 0);
         }
 
-        // Process content blocks from the response
-        const contentBlocks = response.content as AnthropicContentBlock[];
-        const toolUseBlocks: Array<{ id: string; name: string; input: Record<string, unknown> }> = [];
-
-        for (const block of contentBlocks) {
-          if (block.type === 'text' && block.text) {
-            yield { type: 'text', content: block.text };
-          } else if (block.type === 'tool_use') {
+        // Collect tool_use blocks from final response
+        for (const block of response.content) {
+          if (block.type === 'tool_use') {
             yield {
-              type: 'tool_use',
-              toolName: block.name!,
+              type: 'tool_use' as const,
+              toolName: block.name,
               input: (block.input as Record<string, unknown>) ?? {},
             };
             toolUseBlocks.push({
-              id: block.id!,
-              name: block.name!,
+              id: block.id,
+              name: block.name,
               input: (block.input as Record<string, unknown>) ?? {},
             });
           }
@@ -127,14 +148,13 @@ export class ClaudeApiEngine implements AgentEnginePort {
 
         // Check stop reason
         if (response.stop_reason === 'end_turn' || toolUseBlocks.length === 0) {
-          // Extract final text as summary
-          const summaryBlock = contentBlocks.find(
-            (b) => b.type === 'text' && b.text,
+          const summaryBlock = response.content.find(
+            (b: any) => b.type === 'text' && b.text,
           );
-          const summary = summaryBlock?.text ?? 'Task completed';
+          const summary = (summaryBlock as any)?.text ?? 'Task completed';
 
           yield {
-            type: 'completed',
+            type: 'completed' as const,
             summary,
             tokensUsed: totalTokensUsed,
           };

packages/services/agent-service/src/interfaces/rest/controllers/agent.controller.ts

@@ -25,9 +25,12 @@ export class AgentController {
   @Post('tasks')
   async executeTask(
     @TenantId() tenantId: string,
-    @Body() body: { prompt: string; systemPrompt?: string; maxTurns?: number; allowedTools?: string[] },
+    @Body() body: { prompt: string; systemPrompt?: string; maxTurns?: number; allowedTools?: string[]; engineType?: string },
   ) {
-    const engine = this.engineRegistry.getActiveEngine();
+    // Allow callers to override the engine (e.g. voice uses claude_api for streaming)
+    const engine = body.engineType
+      ? this.engineRegistry.switchEngine(body.engineType as AgentEngineType)
+      : this.engineRegistry.getActiveEngine();
 
     const session = new AgentSession();
     session.id = crypto.randomUUID();