feat: 集成豆包 ASR 语音识别后端，支持 /voice doubao 切换 (#357)

* feat: 集成豆包 ASR 语音识别后端，支持 /voice doubao 切换

- 新增 src/services/doubaoSTT.ts 适配模块，将 doubaoime-asr 的
  AsyncGenerator 协议适配为现有 VoiceStreamConnection 接口
- /voice doubao 启用豆包后端，/voice 使用默认 Anthropic 后端
- 后端选择持久化到 settings.json 的 voiceProvider 字段
- 豆包后端跳过 Anthropic OAuth 认证、语言限制和 Focus Mode
- 豆包后端松手即出结果，跳过 processing 状态
- 凭证文件存放在 ~/.claude/tts/doubao/credentials.json
- doubaoime-asr 作为 optionalDependencies 安装
- 移除 /voice 命令的 claude-ai 可用性限制，所有用户可用

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

* docs: 更新 Voice Mode 文档，添加豆包 ASR 后端说明和致谢

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

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

src/utils/settings/types.ts

@@ -880,6 +880,10 @@ export const SettingsSchema = lazySchema(() =>
               .boolean()
               .optional()
               .describe('Enable voice mode (hold-to-talk dictation)'),
+            voiceProvider: z
+              .enum(['anthropic', 'doubao'])
+              .optional()
+              .describe('Voice STT backend: "anthropic" (default) or "doubao" (Doubao ASR)'),
           }
         : {}),
       ...(feature('KAIROS')

src/utils/suggestions/__tests__/commandSuggestions.test.ts

@@ -23,7 +23,7 @@ function makeCommand(name: string, opts?: Partial<Command>): Command {
     type: 'local',
     handler: () => {},
     ...opts,
-  } as Command
+  } as unknown as Command
 }
 
 function makePromptCommand(
@@ -37,7 +37,7 @@ function makePromptCommand(
     handler: () => {},
     source: 'userSettings',
     ...opts,
-  } as Command
+  } as unknown as Command
 }
 
 // ─── isCommandInput ───────────────────────────────────────────────────