feat(license): show Instance ID with copy on settings + ProGate

Always return machine fingerprint instanceId from license status for
offline LICOFF- binding. Shared InstanceIdRow (zh/en) above activate.

frontend/src/components/ProGate.tsx

@@ -6,6 +6,7 @@ import { toast } from 'sonner'
 import { Button } from '@/components/ui/button'
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
 import { Input } from '@/components/ui/input'
+import { InstanceIdRow } from '@/components/InstanceIdRow'
 import { LicenseStatusBanners } from '@/components/LicenseStatusBanners'
 import { licenseApi } from '@/api/license'
 import { useLicense } from '@/hooks/useLicense'
@@ -41,6 +42,7 @@ export const ProGate = memo(function ProGate({ featureKey }: { featureKey: strin
   return (
     <div className="mx-auto max-w-2xl space-y-4 pt-8">
       <LicenseStatusBanners info={info} pro={pro} onAction={focusKey} />
+      <InstanceIdRow instanceId={info?.instanceId} />
       <Card>
         <CardHeader className="pb-3">
           <CardTitle className="flex items-center gap-2 text-base">
@@ -71,16 +73,19 @@ export const ProGate = memo(function ProGate({ featureKey }: { featureKey: strin
               <p className="mt-1 text-xs text-muted-foreground">{t('pricing.teamDesc')}</p>
             </div>
           </div>
-          <div className="flex gap-2">
-            <Input
-              ref={inputRef}
-              value={key}
-              onChange={e => setKey(e.target.value)}
-              placeholder={t('gate.keyPlaceholder')}
-              className="font-mono text-sm"
-            />
-            <Button onClick={() => void activate()} disabled={activating || !key.trim()}>{t('gate.activate')}</Button>
-            <Button variant="outline" onClick={() => navigate('/settings')}>{t('gate.toSettings')}</Button>
+          <div className="space-y-2">
+            <p className="text-xs text-muted-foreground">{t('activateHint')}</p>
+            <div className="flex gap-2">
+              <Input
+                ref={inputRef}
+                value={key}
+                onChange={e => setKey(e.target.value)}
+                placeholder={t('gate.keyPlaceholder')}
+                className="font-mono text-sm"
+              />
+              <Button onClick={() => void activate()} disabled={activating || !key.trim()}>{t('gate.activate')}</Button>
+              <Button variant="outline" onClick={() => navigate('/settings')}>{t('gate.toSettings')}</Button>
+            </div>
           </div>
           <p className="text-xs text-muted-foreground">{t('gate.freeHint')}</p>
         </CardContent>