feat(admin): Convert settings layout to use tabbed navigation, isolating SMTP configuration

client/src/app/admin/settings/page.tsx

@@ -49,6 +49,15 @@ export default function AdminSettingsPage() {
     return acc;
   }, {} as Record<string, Setting[]>);
 
+  const categories = Object.keys(groupedSettings);
+  const [activeTab, setActiveTab] = useState<string>('');
+
+  useEffect(() => {
+    if (categories.length > 0 && !activeTab) {
+      setActiveTab(categories[0]);
+    }
+  }, [categories, activeTab]);
+
   return (
     <div className="p-10 max-w-5xl mx-auto font-sans pb-32">
       <div className="flex flex-col sm:flex-row justify-between items-start sm:items-center mb-10 gap-4">
@@ -72,19 +81,40 @@ export default function AdminSettingsPage() {
         </button>
       </div>
 
+      {categories.length > 0 && (
+        <div className="mb-8 border-b border-gray-200">
+          <nav className="-mb-px flex space-x-8" aria-label="Tabs">
+            {categories.map((category) => (
+              <button
+                key={category}
+                onClick={() => setActiveTab(category)}
+                className={`
+                  whitespace-nowrap py-4 px-1 border-b-2 font-medium text-sm capitalize transition-colors
+                  ${activeTab === category
+                    ? 'border-indigo-500 text-indigo-600'
+                    : 'border-transparent text-gray-500 hover:text-gray-700 hover:border-gray-300'
+                  }
+                `}
+              >
+                {category} Settings
+              </button>
+            ))}
+          </nav>
+        </div>
+      )}
+
       <div className="space-y-8">
-        {Object.keys(groupedSettings).map(category => (
-          <div key={category} className="bg-white rounded-2xl shadow-xl shadow-gray-200/50 border border-gray-200 overflow-hidden relative">
-            
+        {activeTab && groupedSettings[activeTab] && (
+          <div className="bg-white rounded-2xl shadow-xl shadow-gray-200/50 border border-gray-200 overflow-hidden relative animate-in fade-in slide-in-from-bottom-4 duration-500">
             {/* Category Header */}
             <div className="bg-gradient-to-r from-gray-50 to-white px-8 py-5 border-b border-gray-100 flex items-center gap-3">
               <div className="w-2 h-6 bg-indigo-500 rounded-full"></div>
-              <h2 className="text-xl font-bold text-gray-900 capitalize">{category} Configuration</h2>
+              <h2 className="text-xl font-bold text-gray-900 capitalize">{activeTab} Configuration</h2>
             </div>
 
             <div className="p-8 grid grid-cols-1 md:grid-cols-2 gap-8">
-              {groupedSettings[category].map(setting => {
-                const isSecret = setting.key.includes('key') || setting.key.includes('secret') || setting.key.includes('password');
+              {groupedSettings[activeTab].map(setting => {
+                const isSecret = setting.key.includes('key') || setting.key.includes('secret') || setting.key.includes('password') || setting.key.includes('pass');
                 return (
                   <div key={setting.key} className="space-y-2">
                     <label className="block text-sm font-bold text-gray-700 uppercase tracking-wider">
@@ -109,7 +139,7 @@ export default function AdminSettingsPage() {
               })}
             </div>
           </div>
-        ))}
+        )}
       </div>
     </div>
   );