feat(frontend): show active app domain with click-to-copy

Surface the domain the app is actually reachable on right now (verified
custom domain, else the platform subdomain) as a single "Application
Domain" field. Clicking it copies the address to the clipboard and shows
a "Copied" toast. Centralizes the active-domain logic so the page header
and the verified-custom-domain block stay in sync, and always loads
domain-info so the platform host is correct even without a custom domain.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/app/[lang]/dashboard/apps/[id]/page.tsx

@@ -303,7 +303,9 @@ export default function AppDetailPage() {
   }>({
     queryKey: ['domain-info', appId],
     queryFn: () => api.get(`/applications/${appId}/domain`).then((r) => r.data),
-    enabled: showDomainSetup || (!!app && (app.customDomainStatus === 'pending_dns' || app.customDomainStatus === 'verified')),
+    // Always load: we surface the active app domain (platform host included) even
+    // when no custom domain is configured, so the platform host must be available.
+    enabled: !!app,
   });
 
   const { data: domainPriceData } = useQuery<{ monthlyPrice: number }>({
@@ -1045,6 +1047,18 @@ export default function AppDetailPage() {
 
   const pageLocked = isAnyDeleting;
 
+  // The host the app is actually reachable on right now: the verified custom
+  // domain when present, otherwise the platform-assigned subdomain. Single source
+  // of truth so every place that shows "the app's domain" stays in sync.
+  const platformHost = `${app.subdomain}.${domainInfo?.platformDomain || 'apps.cloudhost.ir'}`;
+  const currentDomain =
+    app.customDomain && app.customDomainStatus === 'verified' ? app.customDomain : platformHost;
+
+  const copyDomain = (domain: string) => {
+    navigator.clipboard.writeText(domain);
+    notify.success(ad.copied);
+  };
+
   return (
     <>
       <DeletingModal open={pageLocked} resourceName={app.name} resourceKind="application" />
@@ -1067,10 +1081,7 @@ export default function AppDetailPage() {
             </div>
             <p className="text-sm text-gray-500 truncate">
               {app.runtime}{app.runtimeVersion ? ` v${app.runtimeVersion}` : ''}{app.phpVersion ? ` — PHP ${app.phpVersion}` : ''} ·{' '}
-              {app.customDomain && app.customDomainStatus === 'verified'
-                ? <a href={`https://${app.customDomain}`} target="_blank" rel="noopener noreferrer" className="text-emerald-600 hover:underline">{app.customDomain}</a>
-                : <span>{app.subdomain}.{domainInfo?.platformDomain || 'apps.cloudhost.ir'}</span>
-              }
+              <a href={`https://${currentDomain}`} target="_blank" rel="noopener noreferrer" dir="ltr" className="text-primary-600 hover:underline">{currentDomain}</a>
             </p>
           </div>
         </div>
@@ -1604,16 +1615,24 @@ export default function AppDetailPage() {
           )}
         </div>
 
-        {/* Platform domain (always shown) */}
+        {/* Application domain — the host the app is reachable on right now
+            (verified custom domain, else the platform subdomain). Click to copy. */}
         <div className="bg-gray-50 rounded-xl p-4 mb-4">
-          <div className="flex items-center justify-between">
-            <div>
-              <p className="text-xs text-gray-500 mb-1">{ad.platformDomain}</p>
-              <p className="text-sm font-mono font-medium text-gray-800">
-                {app.subdomain}.{domainInfo?.platformDomain || 'apps.cloudhost.ir'}
-              </p>
+          <div className="flex items-center justify-between gap-3">
+            <div className="min-w-0">
+              <p className="text-xs text-gray-500 mb-1">{ad.appDomain}</p>
+              <button
+                type="button"
+                onClick={() => copyDomain(currentDomain)}
+                title={ad.copyDomainHint}
+                dir="ltr"
+                className="group inline-flex items-center gap-1.5 max-w-full text-sm font-mono font-medium text-gray-800 hover:text-primary-600 transition-colors"
+              >
+                <span className="truncate">{currentDomain}</span>
+                <Copy className="w-3.5 h-3.5 shrink-0 opacity-50 group-hover:opacity-100 transition-opacity" />
+              </button>
             </div>
-            <span className="badge badge-green text-xs">{ad.active}</span>
+            <span className="badge badge-green text-xs shrink-0">{ad.active}</span>
           </div>
         </div>
 
@@ -1623,7 +1642,16 @@ export default function AppDetailPage() {
             <div className="flex items-center justify-between">
               <div>
                 <p className="text-xs text-emerald-600 mb-1">{ad.customDomain}</p>
-                <p className="text-sm font-mono font-medium text-emerald-800">{app.customDomain}</p>
+                <button
+                  type="button"
+                  onClick={() => copyDomain(app.customDomain!)}
+                  title={ad.copyDomainHint}
+                  dir="ltr"
+                  className="group inline-flex items-center gap-1.5 max-w-full text-sm font-mono font-medium text-emerald-800 hover:text-emerald-600 transition-colors"
+                >
+                  <span className="truncate">{app.customDomain}</span>
+                  <Copy className="w-3.5 h-3.5 shrink-0 opacity-50 group-hover:opacity-100 transition-opacity" />
+                </button>
                 <p className="text-xs text-emerald-500 mt-1">
                   <CheckCircle className="w-3 h-3 inline" /> SSL Active — Verified on{' '}
                   {app.customDomainVerifiedAt ? new Date(app.customDomainVerifiedAt).toLocaleString(locale) : ''}