feat: Implement initial backend API server with various endpoints and background services, including an error account cleaner.

backend/cmd/main.go

@@ -508,7 +508,7 @@ func handleS2ATest(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// 请求 S2A 仪表盘接口
-	dashboardURL := config.Global.S2AApiBase + "/api/v1/admin/dashboard"
+	dashboardURL := config.Global.S2AApiBase + "/api/v1/admin/dashboard/stats"
 	req, err := http.NewRequest("GET", dashboardURL, nil)
 	if err != nil {
 		api.Error(w, http.StatusInternalServerError, "创建请求失败")

backend/internal/api/error_cleaner.go

@@ -75,7 +75,7 @@ func getTotalAccountCount() (int, error) {
 	}
 
 	client := &http.Client{Timeout: 30 * time.Second}
-	url := fmt.Sprintf("%s/api/v1/admin/dashboard", config.Global.S2AApiBase)
+	url := fmt.Sprintf("%s/api/v1/admin/dashboard/stats", config.Global.S2AApiBase)
 
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {