feat: implement visual analytics and activity charts

web/src/server.ts

@@ -59,6 +59,10 @@ export async function createWebServer(config: WebServerConfig = {}): Promise<Web
     // Interval for broadcasting stats to all connected WS clients
     let statsBroadcastInterval: Timer | undefined;
 
+    // Cache for activity stats (heavy aggregation)
+    let cachedActivity: { data: any, timestamp: number } | null = null;
+    const ACTIVITY_CACHE_TTL = 5 * 60 * 1000; // 5 minutes
+
     const server = serve({
         port,
         hostname,
@@ -97,6 +101,27 @@ export async function createWebServer(config: WebServerConfig = {}): Promise<Web
                 }
             }
 
+            if (url.pathname === "/api/stats/activity") {
+                try {
+                    const now = Date.now();
+                    if (cachedActivity && (now - cachedActivity.timestamp < ACTIVITY_CACHE_TTL)) {
+                        return Response.json(cachedActivity.data);
+                    }
+
+                    const { dashboardService } = await import("@shared/modules/dashboard/dashboard.service");
+                    const activity = await dashboardService.getActivityAggregation();
+
+                    cachedActivity = { data: activity, timestamp: now };
+                    return Response.json(activity);
+                } catch (error) {
+                    console.error("Error fetching activity stats:", error);
+                    return Response.json(
+                        { error: "Failed to fetch activity statistics" },
+                        { status: 500 }
+                    );
+                }
+            }
+
             // Administrative Actions
             if (url.pathname.startsWith("/api/actions/") && req.method === "POST") {
                 try {