feat(openai): Mobile RT 补全 plan_type、精确匹配账号、刷新时自动设置隐私

1. accounts/check 补全 plan_type：当 id_token 缺少 plan_type（如 Mobile RT），
   自动调用 accounts/check 端点获取订阅类型
2. orgID 精确匹配账号：从 JWT 提取 poid 匹配正确账号，避免 Go map
   遍历顺序随机导致 plan_type 不稳定
3. RT 刷新时设置隐私：调用 disableOpenAITraining 关闭训练数据共享，
   结果存入 extra.privacy_mode，后续跳过重复设置

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/cmd/server/wire_gen.go

@@ -114,6 +114,7 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	oAuthService := service.NewOAuthService(proxyRepository, claudeOAuthClient)
 	openAIOAuthClient := repository.NewOpenAIOAuthClient()
 	openAIOAuthService := service.NewOpenAIOAuthService(proxyRepository, openAIOAuthClient)
+	openAIOAuthService.SetPrivacyClientFactory(privacyClientFactory)
 	geminiOAuthClient := repository.NewGeminiOAuthClient(configConfig)
 	geminiCliCodeAssistClient := repository.NewGeminiCliCodeAssistClient()
 	driveClient := repository.NewGeminiDriveClient()