feat(diagnostic): refactor services with monitor and context providers

- Update default-diagnostic-service.ts

- Update diagnostic-monitor-context.tsx

- Update diagnostic-service-context.tsx

- Update monitored-diagnostic-service.ts

- Update teacher diagnostic page

src/modules/diagnostic/services/diagnostic-service-context.tsx

@@ -1,8 +1,12 @@
 "use client"
 
-import { createContext, useContext, type ReactNode } from "react"
+import { createContext, useContext, useMemo, type ReactNode } from "react"
 
 import type { DiagnosticService } from "./diagnostic-service"
+import { defaultDiagnosticService } from "./default-diagnostic-service"
+import { createMonitoredDiagnosticService } from "./monitored-diagnostic-service"
+import { noopDiagnosticMonitor } from "./diagnostic-monitor"
+import { useDiagnosticMonitor } from "./diagnostic-monitor-context"
 
 /**
  * v2-P1-4: 诊断模块服务 Context。
@@ -10,13 +14,14 @@ import type { DiagnosticService } from "./diagnostic-service"
  * 组件通过 useDiagnosticService() 获取服务实现，
  * 而非直接 import actions，实现依赖反转。
  *
- * 默认由 DefaultDiagnosticServiceProvider 注入真实实现（调用 Server Actions）；
+ * 默认由 DiagnosticServiceProvider 在客户端组装默认实现（调用 Server Actions）；
  * 测试时可注入 mock 实现以隔离组件测试。
  */
 const DiagnosticServiceContext = createContext<DiagnosticService | null>(null)
 
 interface DiagnosticServiceProviderProps {
-  service: DiagnosticService
+  /** 可选自定义服务实现，未传则使用 defaultDiagnosticService + 监控包装 */
+  service?: DiagnosticService
   children: ReactNode
 }
 
@@ -24,8 +29,18 @@ export function DiagnosticServiceProvider({
   service,
   children,
 }: DiagnosticServiceProviderProps): ReactNode {
+  const monitor = useDiagnosticMonitor()
+  const value = useMemo<DiagnosticService>(() => {
+    if (service) return service
+    // 客户端组装：默认 service + 监控埋点包装
+    return createMonitoredDiagnosticService(
+      defaultDiagnosticService,
+      monitor ?? noopDiagnosticMonitor,
+    )
+  }, [service, monitor])
+
   return (
-    <DiagnosticServiceContext.Provider value={service}>
+    <DiagnosticServiceContext.Provider value={value}>
       {children}
     </DiagnosticServiceContext.Provider>
   )