feat(ui): unify card typography across application

frontend/components/admin/CategoryManager.tsx

@@ -43,8 +43,8 @@ export default function CategoryManager({
          {categories.map(cat => (
            <div key={cat.id} className="p-4 bg-slate-950/40 border border-slate-800/50 rounded-2xl flex items-center justify-between group hover:border-primary/40 transition-all">
              <div className="min-w-0 pr-4">
-               <p className="text-sm font-bold text-slate-200 group-hover:text-primary transition-colors">{cat.name}</p>
-               <p className="text-xs text-slate-500 font-medium mt-0.5">{cat.description || 'General storage'}</p>
+               <p className="card-title group-hover:text-primary transition-colors">{cat.name}</p>
+               <p className="card-subtitle">{cat.description || 'General storage'}</p>
              </div>
              <div className="flex gap-1 shrink-0">
                 <button