refactor: consolidate icons and move server edit to separate page

- Create centralized icons file at src/components/icons/index.tsx
- Update admin and AppShell icons to re-export from centralized location
- Replace trial "T" button with GiftIcon in AdminServers
- Move server editing from modal to dedicated page /admin/servers/:id/edit
- Add localization keys for server edit page (mainSettings, pricingAndLimits, updateError)

src/App.tsx

@@ -37,6 +37,7 @@ const AdminWheel = lazy(() => import('./pages/AdminWheel'));
 const AdminTariffs = lazy(() => import('./pages/AdminTariffs'));
 const AdminTariffCreate = lazy(() => import('./pages/AdminTariffCreate'));
 const AdminServers = lazy(() => import('./pages/AdminServers'));
+const AdminServerEdit = lazy(() => import('./pages/AdminServerEdit'));
 const AdminDashboard = lazy(() => import('./pages/AdminDashboard'));
 const AdminBanSystem = lazy(() => import('./pages/AdminBanSystem'));
 const AdminBroadcasts = lazy(() => import('./pages/AdminBroadcasts'));
@@ -338,6 +339,16 @@ function App() {
             </AdminRoute>
           }
         />
+        <Route
+          path="/admin/servers/:id/edit"
+          element={
+            <AdminRoute>
+              <LazyPage>
+                <AdminServerEdit />
+              </LazyPage>
+            </AdminRoute>
+          }
+        />
         <Route
           path="/admin/dashboard"
           element={