feat: redesign admin panel with Lucide icons and modern styling

- Add lucide-react for SVG icons throughout the admin
- Redesign sidebar with gradient background, icons per nav item, and sticky layout
- Redesign topbar with cleaner user info display
- Redesign dashboard with icon-backed stat cards, gradient progress bars, activity feed
- Update AdminNavLink with icon support and new active state styling
- Improve table styling in admin-page CSS (rounded corners, hover, spacing)
- Clean up unused admin CSS

pnpm-lock.yaml

@@ -23,6 +23,9 @@ importers:
       hash-wasm:
         specifier: ^4.12.0
         version: 4.12.0
+      lucide-react:
+        specifier: ^1.23.0
+        version: 1.23.0([email protected])
       next:
         specifier: ^16.2.9
         version: 16.2.9([email protected]([email protected]))([email protected])
@@ -2125,6 +2128,11 @@ packages:
     resolution: {integrity: sha512-DqC6n3QQ77zdFpCMASA1a3Jlb64Hv2N2DciFGkO/4L9+q/IpIAuRlKOvCXabtRW6cQf8usbmM6BE/TOPysCdIA==}
     engines: {bun: '>=1.0.0', deno: '>=1.30.0', node: '>=8.0.0'}
 
+  [email protected]:
+    resolution: {integrity: sha512-38BpJcD0JhFosxHApP/BYsBetLpQFRoTRzEzstM/XCc3jsAG7wqaY1lgVwxiUe3xqYE+lNxo2PkCmYwXWrwwIw==}
+    peerDependencies:
+      react: ^16.5.1 || ^17.0.0 || ^18.0.0 || ^19.0.0
+
   [email protected]:
     resolution: {integrity: sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==}
 
@@ -4012,6 +4020,10 @@ snapshots:
 
   [email protected]: {}
 
+  [email protected]([email protected]):
+    dependencies:
+      react: 19.2.7
+
   [email protected]:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5