feat: 语音流式输入管线 + VAD前端集成 + 插件-工具合并清理

- 前端: VAD语音检测(@ricky0123/vad-web) + useVoiceInput双模式(流式WS/REST)
- Gateway: VoiceStreamManager代理WS流式STT到voice-service
- Voice-service: DashScope REST → Realtime WS → Whisper三级引擎 + ffmpeg转码
- 共享模块: pkg/audio(音频转换) + pkg/dashscope(ASR REST客户端)
- 清理: 移除旧plugin-manager和pkg/plugins，完成插件→工具合并
- 文档: 完善gateway-api.md和voice-service.md语音API文档
- 工具: scripts/voice/ 语音转换脚本集

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/voice-service/internal/service/dashscope_stt.go

@@ -5,12 +5,10 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"os"
-	"os/exec"
-	"strings"
 	"sync"
 	"time"
 
+	"git.yeij.top/AskaEth/Cyrene/pkg/audio"
 	"github.com/gorilla/websocket"
 )
 
@@ -145,7 +143,7 @@ func (d *DashScopeSTT) Transcribe(ctx context.Context, audioData []byte, format
 	}
 
 	// 4. 规范化音频格式并发送
-	pcmData, err := convertToPCM16(audioData, format)
+	pcmData, err := audio.ConvertToPCM16(audioData, format)
 	if err != nil {
 		return "", fmt.Errorf("音频格式转换失败: %w", err)
 	}
@@ -447,74 +445,3 @@ func (d *DashScopeSTT) GetStatus() map[string]interface{} {
 		"provider":  "dashscope",
 	}
 }
-
-// normalizeSTTFormat 规范化音频格式字符串。
-func normalizeSTTFormat(format string) string {
-	switch strings.ToLower(format) {
-	case "pcm", "wav", "mp3", "mpeg", "ogg", "opus", "flac", "m4a", "mp4", "aac", "webm":
-		return strings.ToLower(format)
-	default:
-		return format
-	}
-}
-
-// convertToPCM16 将音频数据转换为 16-bit PCM 16000Hz mono。
-func convertToPCM16(data []byte, format string) ([]byte, error) {
-	normFormat := normalizeSTTFormat(format)
-	switch normFormat {
-	case "pcm":
-		return data, nil
-	case "wav":
-		if len(data) > 44 {
-			return data[44:], nil
-		}
-		return data, nil
-	default:
-		return transcodeToPCM(data, normFormat)
-	}
-}
-
-// transcodeToPCM 使用 ffmpeg 将音频数据转码为 PCM 16-bit 16000Hz mono。
-func transcodeToPCM(data []byte, format string) ([]byte, error) {
-	inFile, err := os.CreateTemp(os.TempDir(), "cyrene-asr-in-*."+format)
-	if err != nil {
-		return nil, fmt.Errorf("创建输入临时文件失败: %w", err)
-	}
-	inPath := inFile.Name()
-	defer os.Remove(inPath)
-	if _, err := inFile.Write(data); err != nil {
-		inFile.Close()
-		return nil, fmt.Errorf("写入输入临时文件失败: %w", err)
-	}
-	inFile.Close()
-
-	outFile, err := os.CreateTemp(os.TempDir(), "cyrene-asr-out-*.pcm")
-	if err != nil {
-		return nil, fmt.Errorf("创建输出临时文件失败: %w", err)
-	}
-	outPath := outFile.Name()
-	outFile.Close()
-	defer os.Remove(outPath)
-
-	cmd := exec.Command("ffmpeg",
-		"-i", inPath,
-		"-ar", "16000",
-		"-ac", "1",
-		"-c:a", "pcm_s16le",
-		"-f", "s16le",
-		outPath,
-		"-y",
-	)
-	cmd.Stderr = nil
-
-	if err := cmd.Run(); err != nil {
-		return nil, fmt.Errorf("音频转码失败 (ffmpeg): %w", err)
-	}
-
-	outData, err := os.ReadFile(outPath)
-	if err != nil {
-		return nil, fmt.Errorf("读取转码结果失败: %w", err)
-	}
-
-	return outData, nil
-}