refactor: remove unused pages and components, streamline Admin and Dashboard functionality

src/App.tsx

@@ -5,7 +5,6 @@ import { AuthProvider } from '@/components/AuthProvider'
 import { SocketProvider } from '@/contexts/SocketContext'
 import { MusicPlayerProvider } from '@/contexts/MusicPlayerContext'
 import { AccountPage } from '@/pages/AccountPage'
-import { ActivityPage } from '@/pages/ActivityPage'
 import { AdminUsersPage } from '@/pages/AdminUsersPage'
 import { AdminSoundsPage } from '@/pages/AdminSoundsPage'
 import { DashboardPage } from '@/pages/DashboardPage'
@@ -42,19 +41,6 @@ function App() {
                 </ProtectedRoute>
               }
             />
-            <Route
-              path="/activity"
-              element={
-                <ProtectedRoute>
-                  <AppLayout
-                    title="Activity"
-                    description="View recent activity and logs"
-                  >
-                    <ActivityPage />
-                  </AppLayout>
-                </ProtectedRoute>
-              }
-            />
             <Route
               path="/account"
               element={
@@ -81,20 +67,6 @@ function App() {
                 </ProtectedRoute>
               }
             />
-            <Route
-              path="/admin/users"
-              element={
-                <ProtectedRoute requireAdmin>
-                  <AppLayout
-                    title="User Management"
-                    description="Manage users and their permissions"
-                    headerActions={<Button>Add User</Button>}
-                  >
-                    <AdminUsersPage />
-                  </AppLayout>
-                </ProtectedRoute>
-              }
-            />
             <Route
               path="/admin/sounds"
               element={