feat(ui): add themed shell navigation

lib/pages/settings_page.dart

@@ -1,50 +1,54 @@
 import 'package:flutter/material.dart';
-import 'package:go_router/go_router.dart';
 
 class SettingsPage extends StatelessWidget {
   const SettingsPage({super.key});
 
   @override
   Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Settings'),
-        leading: IconButton(
-          icon: const Icon(Icons.arrow_back),
-          onPressed: () => context.go('/'),
+    return ListView(
+      padding: const EdgeInsets.fromLTRB(20, 16, 20, 24),
+      children: [
+        Text(
+          'Settings',
+          style: Theme.of(context).textTheme.headlineMedium?.copyWith(
+                fontWeight: FontWeight.w700,
+              ),
         ),
-      ),
-      body: ListView(
-        children: [
-          ListTile(
-            leading: const Icon(Icons.brightness_6),
-            title: const Text('Theme'),
-            subtitle: const Text('Change app theme'),
-            trailing: const Icon(Icons.chevron_right),
-            onTap: () {
-              // Theme settings functionality
-            },
+        const SizedBox(height: 6),
+        Text(
+          'Theme, Bluetooth, and app details.',
+          style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: Theme.of(context)
+                    .colorScheme
+                    .onSurface
+                    .withValues(alpha: 0.68),
+              ),
+        ),
+        const SizedBox(height: 20),
+        Card(
+          child: Column(
+            children: const [
+              ListTile(
+                leading: Icon(Icons.brightness_6),
+                title: Text('Theme'),
+                subtitle: Text('Theme controls arrive in the next phase'),
+              ),
+              Divider(height: 1),
+              ListTile(
+                leading: Icon(Icons.bluetooth),
+                title: Text('Bluetooth Settings'),
+                subtitle: Text('Configure Bluetooth connections'),
+              ),
+              Divider(height: 1),
+              ListTile(
+                leading: Icon(Icons.info),
+                title: Text('About'),
+                subtitle: Text('App information'),
+              ),
+            ],
           ),
-          ListTile(
-            leading: const Icon(Icons.bluetooth),
-            title: const Text('Bluetooth Settings'),
-            subtitle: const Text('Configure Bluetooth connections'),
-            trailing: const Icon(Icons.chevron_right),
-            onTap: () {
-              // Bluetooth settings functionality
-            },
-          ),
-          ListTile(
-            leading: const Icon(Icons.info),
-            title: const Text('About'),
-            subtitle: const Text('App information'),
-            trailing: const Icon(Icons.chevron_right),
-            onTap: () {
-              // About screen functionality
-            },
-          ),
-        ],
-      ),
+        ),
+      ],
     );
   }
 }