feat: stabilize admin dashboard, refactor group management, implement PWA, and fix routing

app/server/api/users/[id]/activity.get.ts

@@ -8,10 +8,23 @@ export default defineEventHandler(async (event) => {
   }
 
   // Get user's recent activities
-  const userActivities = Array.from(activities.values())
-    .filter(activity => activity.userId === userId)
-    .sort((a, b) => new Date(b.timestamp).getTime() - new Date(a.timestamp).getTime())
-    .slice(0, 50) // Limit to 50 most recent
+  const user = await prisma.user.findFirst({
+    where: {
+      OR: [{ id: userId }, { username: userId }]
+    }
+  })
+
+  if (!user) {
+    throw createError({ statusCode: 404, message: 'User not found' })
+  }
+
+  // Get user's activities from database or memory
+  const userActivities = await prisma.activity.findMany({
+    where: { userId: user.id },
+    orderBy: { timestamp: 'desc' },
+    take: 20
+  })
+ // Limit to 50 most recent
 
   return { activities: userActivities }
 })