Static service detail: drop the duplicate Subdomain field

A static showed both 'Served at' (from the static block) and 'Subdomain' (the
general proxied-service field) — same URL twice. Gate 'Subdomain' to non-static;
a static's gateway URL is already 'Served at'.

app/src/pages/ServiceDetail.tsx

@@ -101,7 +101,9 @@ export function ServiceDetailPage() {
               <span className="font-mono break-all">{deployment.health_path}</span>
             </>
           )}
-          {deployment.subdomain && (
+          {/* A static already shows its gateway URL as "Served at" above; only a
+              proxied (systemd) service surfaces the same thing as "Subdomain". */}
+          {!isStatic && deployment.subdomain && (
             <>
               <span className="text-[var(--muted)]">Subdomain</span>
               <a