feat(license): Lizenz-System mit Ed25519-Verify gegen license.netcell-it.com

Portiert mail-gateway/internal/license (Verify, Cache, Trial, Signature)
+ DB-Mirror (internal/services/license) + REST-Handler (status/verify/key/clear)
+ UI-Page /license (Activate, Status, Limits, Features, Re-verify)
+ <LicenseBanner /> neben UpdateBanner (trial-expiring, expired, verify-failed)
+ Scheduler: täglich Re-verify (24h-Tick)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

management-ui/src/components/Layout/AppLayout.tsx

@@ -5,6 +5,7 @@ import { useTranslation } from 'react-i18next'
 import Sidebar from './Sidebar'
 import Header from './Header'
 import UpdateBanner from '../UpdateBanner'
+import LicenseBanner from '../LicenseBanner'
 
 // PAGE_TITLES maps the pathname to an i18n nav key. Header reads
 // this to render "where you are". Empty fallback = app.title.
@@ -16,6 +17,7 @@ const PAGE_TITLES: Record<string, string> = {
   '/networks':      'nav.networks',
   '/ip-addresses':  'nav.ipAddresses',
   '/cluster':       'nav.cluster',
+  '/license':       'nav.license',
   '/settings':      'nav.settings',
 }
 
@@ -42,6 +44,7 @@ export default function AppLayout() {
 
       <main className="main-content">
         <Header pageTitle={title} onMenuToggle={() => setSidebarOpen(true)} />
+        <LicenseBanner />
         <UpdateBanner />
         <div className="content-area">
           <Outlet />

management-ui/src/components/Layout/Sidebar.tsx

@@ -5,6 +5,7 @@ import {
   ClockCircleOutlined,
   CloudServerOutlined,
   ClusterOutlined,
+  CrownOutlined,
   DashboardOutlined,
   DatabaseOutlined,
   FireOutlined,
@@ -70,12 +71,13 @@ const NAV: NavSection[] = [
     labelKey: 'nav.section.system',
     items: [
       { path: '/cluster',  labelKey: 'nav.cluster',  icon: <ApartmentOutlined /> },
+      { path: '/license',  labelKey: 'nav.license',  icon: <CrownOutlined /> },
       { path: '/settings', labelKey: 'nav.settings', icon: <SettingOutlined /> },
     ],
   },
 ]
 
-const VERSION = '1.0.46'
+const VERSION = '1.0.47'
 
 export default function Sidebar({ isOpen, onClose }: SidebarProps) {
   const { t } = useTranslation()

management-ui/src/components/LicenseBanner.tsx

@@ -0,0 +1,91 @@
+import { Alert } from 'antd'
+import { Link } from 'react-router-dom'
+import { useQuery } from '@tanstack/react-query'
+import { useTranslation } from 'react-i18next'
+
+import apiClient, { isEnvelope } from '../api/client'
+
+interface LicenseStatus {
+  license_key?: string
+  status: string
+  type?: string
+  valid_until?: string
+  expires_at?: string
+  last_error?: string | null
+}
+
+// LicenseBanner shows up in AppLayout next to UpdateBanner.
+// Three visible states:
+//  - trial-expiring (≤14d remaining) → warning
+//  - expired / invalid → error
+//  - last verify failed → warning (transient)
+// Everything else stays silent.
+export default function LicenseBanner() {
+  const { t } = useTranslation()
+
+  const { data: s } = useQuery({
+    queryKey: ['license', 'status'],
+    queryFn: async () => {
+      const r = await apiClient.get('/license/status')
+      return isEnvelope(r.data) ? (r.data.data as LicenseStatus) : null
+    },
+    refetchInterval: 5 * 60 * 1000,
+  })
+
+  if (!s) return null
+
+  const expiry = s.valid_until || s.expires_at
+  const days = expiry ? Math.ceil((new Date(expiry).getTime() - Date.now()) / 86_400_000) : null
+  const isTrial = s.type === 'trial' || !s.license_key
+
+  if (s.status === 'expired' || s.status === 'invalid') {
+    return (
+      <Alert
+        type="error"
+        showIcon
+        banner
+        message={
+          <>
+            {t('licenseBanner.expired')}{' '}
+            <Link to="/license">{t('licenseBanner.cta')}</Link>
+          </>
+        }
+      />
+    )
+  }
+
+  if (isTrial && days !== null && days <= 14) {
+    return (
+      <Alert
+        type={days <= 3 ? 'error' : 'warning'}
+        showIcon
+        banner
+        message={
+          <>
+            {t('licenseBanner.trialExpiring', { days })}{' '}
+            <Link to="/license">{t('licenseBanner.cta')}</Link>
+          </>
+        }
+      />
+    )
+  }
+
+  if (s.last_error) {
+    return (
+      <Alert
+        type="warning"
+        showIcon
+        banner
+        message={
+          <>
+            {t('licenseBanner.verifyFailed')}: {s.last_error}{' '}
+            <Link to="/license">{t('licenseBanner.openPage')}</Link>
+          </>
+        }
+        closable
+      />
+    )
+  }
+
+  return null
+}