fix: increase subtitle font sizes for better readability on desktop

- DatabaseManager: 'Retention & Maintenance' text-xs (12px) → text-sm (14px)
- globals.css: .card-subtitle text-[10px] → text-xs (12px)

Improves readability of secondary headings across admin panels.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

frontend/app/globals.css

@@ -61,7 +61,7 @@ h1, h2, h3, h4, h5, h6 {
   }
   
   .card-subtitle {
-     @apply text-[10px] font-bold text-slate-500 tracking-[0.08em] mt-0.5;
+     @apply text-xs font-bold text-slate-500 tracking-[0.08em] mt-0.5;
   }
 }
 

frontend/components/admin/DatabaseManager.tsx

@@ -78,7 +78,7 @@ export default function DatabaseManager({
              </div>
              <div>
                 <h3 className="text-lg font-black text-white tracking-tight">Storage Policy</h3>
-                <p className="text-xs text-secondary font-bold tracking-tight">Retention & Maintenance</p>
+                <p className="text-sm text-secondary font-bold tracking-tight">Retention & Maintenance</p>
               </div>
           </div>