feat(monitor): admin channel monitor MVP with SSRF protection and batch aggregation

新增 admin「渠道监控」模块（参考 BingZi-233/check-cx），独立于现有 Channel 体系。
admin 配置 + 后台定时调用上游 LLM chat completions 健康检查 + 所有登录用户只读可见。

后端：
- ent: channel_monitor + channel_monitor_history（AES-256-GCM 加密 api_key）
- service 按职责拆分：service/aggregator/validate/checker/runner/ssrf
- provider strategy map 替代 switch（openai/anthropic/gemini）
- repository batch 聚合（ListLatestForMonitorIDs + ComputeAvailabilityForMonitors）消除 N+1
- runner: ticker(5s) + pond worker pool(5) + inFlight 防并发 + TrySubmit 防雪崩
  + 凌晨 3 点 cron 清理 30 天历史
- SSRF 防护：强制 https + 私网/loopback/云元数据 IP 拒绝（127/8、10/8、172.16/12、
  192.168/16、169.254/16、100.64/10、::1、fc00::/7、fe80::/10）+ DialContext
  在 socket 层防 DNS rebinding
- API key sanitize：擦除 url.Error 与上游响应 body 中的 sk-/sk-ant-/AIza/JWT 模式
- APIKeyDecryptFailed 标志位 + 单 monitor 路径检测，避免空 key 调用上游

handler:
- admin: CRUD + 手动触发 + 历史接口（api_key 脱敏）
- user: 只读列表 + 状态详情（去除 api_key/endpoint）
- ParseChannelMonitorID 共用 + dto.ChannelMonitorExtraModelStatus 共用

前端：
- 路由 /admin/channels/{pricing,monitor} + /monitor（用户只读）
- AppSidebar 父项 expandOnly 支持
- ChannelMonitorView 拆为 8 个子组件 + ChannelStatusView 拆出 detail dialog
- composables/useChannelMonitorFormat + constants/channelMonitor 共享
- i18n monitorCommon namespace 消除 admin/user 两 view 重复

合规：所有文件符合 CLAUDE.md（Go ≤ 500 行 / Vue ≤ 300 行 / 函数 ≤ 30 行）
CI: go build / gofmt / golangci-lint(0 issues) / make test-unit / pnpm build 全绿

backend/cmd/server/wire_gen.go

@@ -210,6 +210,16 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	scheduledTestService := service.ProvideScheduledTestService(scheduledTestPlanRepository, scheduledTestResultRepository)
 	scheduledTestHandler := admin.NewScheduledTestHandler(scheduledTestService)
 	channelHandler := admin.NewChannelHandler(channelService, billingService)
+	sqlDB, err := repository.ProvideSQLDB(client)
+	if err != nil {
+		return nil, err
+	}
+	channelMonitorRepository := repository.NewChannelMonitorRepository(client, sqlDB)
+	channelMonitorService := service.ProvideChannelMonitorService(channelMonitorRepository, secretEncryptor)
+	channelMonitorHandler := admin.NewChannelMonitorHandler(channelMonitorService)
+	channelMonitorUserHandler := handler.NewChannelMonitorUserHandler(channelMonitorService)
+	channelMonitorRunner := service.ProvideChannelMonitorRunner(channelMonitorService)
+	_ = channelMonitorRunner
 	registry := payment.ProvideRegistry()
 	encryptionKey, err := payment.ProvideEncryptionKey(configConfig)
 	if err != nil {
@@ -221,7 +231,7 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	settingHandler := admin.NewSettingHandler(settingService, emailService, turnstileService, opsService, paymentConfigService, paymentService)
 	paymentOrderExpiryService := service.ProvidePaymentOrderExpiryService(paymentService)
 	paymentHandler := admin.NewPaymentHandler(paymentService, paymentConfigService)
-	adminHandlers := handler.ProvideAdminHandlers(dashboardHandler, adminUserHandler, groupHandler, accountHandler, adminAnnouncementHandler, dataManagementHandler, backupHandler, oAuthHandler, openAIOAuthHandler, geminiOAuthHandler, antigravityOAuthHandler, proxyHandler, adminRedeemHandler, promoHandler, settingHandler, opsHandler, systemHandler, adminSubscriptionHandler, adminUsageHandler, userAttributeHandler, errorPassthroughHandler, tlsFingerprintProfileHandler, adminAPIKeyHandler, scheduledTestHandler, channelHandler, paymentHandler)
+	adminHandlers := handler.ProvideAdminHandlers(dashboardHandler, adminUserHandler, groupHandler, accountHandler, adminAnnouncementHandler, dataManagementHandler, backupHandler, oAuthHandler, openAIOAuthHandler, geminiOAuthHandler, antigravityOAuthHandler, proxyHandler, adminRedeemHandler, promoHandler, settingHandler, opsHandler, systemHandler, adminSubscriptionHandler, adminUsageHandler, userAttributeHandler, errorPassthroughHandler, tlsFingerprintProfileHandler, adminAPIKeyHandler, scheduledTestHandler, channelHandler, channelMonitorHandler, paymentHandler)
 	usageRecordWorkerPool := service.NewUsageRecordWorkerPool(configConfig)
 	userMsgQueueCache := repository.NewUserMsgQueueCache(redisClient)
 	userMessageQueueService := service.ProvideUserMessageQueueService(userMsgQueueCache, rpmCache, configConfig)
@@ -233,7 +243,7 @@ func initializeApplication(buildInfo handler.BuildInfo) (*Application, error) {
 	paymentWebhookHandler := handler.NewPaymentWebhookHandler(paymentService, registry)
 	idempotencyCoordinator := service.ProvideIdempotencyCoordinator(idempotencyRepository, configConfig)
 	idempotencyCleanupService := service.ProvideIdempotencyCleanupService(idempotencyRepository, configConfig)
-	handlers := handler.ProvideHandlers(authHandler, userHandler, apiKeyHandler, usageHandler, redeemHandler, subscriptionHandler, announcementHandler, adminHandlers, gatewayHandler, openAIGatewayHandler, handlerSettingHandler, totpHandler, handlerPaymentHandler, paymentWebhookHandler, idempotencyCoordinator, idempotencyCleanupService)
+	handlers := handler.ProvideHandlers(authHandler, userHandler, apiKeyHandler, usageHandler, redeemHandler, subscriptionHandler, announcementHandler, channelMonitorUserHandler, adminHandlers, gatewayHandler, openAIGatewayHandler, handlerSettingHandler, totpHandler, handlerPaymentHandler, paymentWebhookHandler, idempotencyCoordinator, idempotencyCleanupService)
 	jwtAuthMiddleware := middleware.NewJWTAuthMiddleware(authService, userService)
 	adminAuthMiddleware := middleware.NewAdminAuthMiddleware(authService, userService, settingService)
 	apiKeyAuthMiddleware := middleware.NewAPIKeyAuthMiddleware(apiKeyService, subscriptionService, configConfig)