fix(i18n): hardkodierte Strings in Cluster/Users/Backups/Alerts bereinigen

- Cluster: statusTag() bekommt t-Parameter; Status-Labels (online/offline/
  joining/leaving/unknown) → cluster.status.* Keys
- Users: 'You'-Tag → t('users.you') / de: 'Ich'
- Backups: 'OK'-Status-Tag → t('backups.okTag')
- Alerts: Kanal-Kind-Labels + alle SMTP-Formular-Labels in t() überführt
- en/de: cluster.status.*, users.you, backups.okTag, alerts.smtp.*,
  alerts.kindWebhook/kindEmail ergänzt

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

management-ui/src/pages/Alerts/index.tsx

@@ -342,8 +342,8 @@ export default function AlertsPage() {
           </Form.Item>
           <Form.Item label={t('alerts.col.kind')} name="kind" rules={[{ required: true }]}>
             <Select options={[
-              { value: 'webhook', label: 'Webhook (Slack/Discord/Teams/HTTP-Endpoint)' },
-              { value: 'email',   label: 'Email (SMTP)' },
+              { value: 'webhook', label: t('alerts.kindWebhook') },
+              { value: 'email',   label: t('alerts.kindEmail') },
             ]} />
           </Form.Item>
           <Form.Item label={kind === 'email' ? t('alerts.col.targetEmail') : t('alerts.col.targetWebhook')}
@@ -353,22 +353,22 @@ export default function AlertsPage() {
 
           {kind === 'email' && (
             <>
-              <Form.Item label="SMTP-Host" name="smtp_host" rules={[{ required: true }]}>
+              <Form.Item label={t('alerts.smtp.host')} name="smtp_host" rules={[{ required: true }]}>
                 <Input placeholder="smtp.gmail.com" />
               </Form.Item>
-              <Form.Item label="SMTP-Port" name="smtp_port" rules={[{ required: true }]}>
+              <Form.Item label={t('alerts.smtp.port')} name="smtp_port" rules={[{ required: true }]}>
                 <InputNumber min={1} max={65535} style={{ width: '100%' }} />
               </Form.Item>
-              <Form.Item label="From" name="from" rules={[{ required: true }]}>
+              <Form.Item label={t('alerts.smtp.from')} name="from" rules={[{ required: true }]}>
                 <Input placeholder="edgeguard@your-domain.tld" />
               </Form.Item>
-              <Form.Item label="Username" name="username">
+              <Form.Item label={t('alerts.smtp.username')} name="username">
                 <Input />
               </Form.Item>
-              <Form.Item label="Password" name="password">
+              <Form.Item label={t('alerts.smtp.password')} name="password">
                 <Input.Password />
               </Form.Item>
-              <Form.Item label="STARTTLS" name="use_tls" valuePropName="checked">
+              <Form.Item label={t('alerts.smtp.starttls')} name="use_tls" valuePropName="checked">
                 <Switch />
               </Form.Item>
             </>

management-ui/src/pages/Backups/History.tsx

@@ -187,7 +187,7 @@ export default function HistoryTab() {
       title: t('backups.col.status'), dataIndex: 'status', width: 110,
       render: (s: Backup['status'], row) =>
         s === 'success'
-          ? <Tag color="green">OK</Tag>
+          ? <Tag color="green">{t('backups.okTag')}</Tag>
           : (
             <Tooltip title={row.error}>
               <Tag color="red">{t('backups.failedTag')}</Tag>

management-ui/src/pages/Cluster/index.tsx

@@ -82,13 +82,13 @@ interface CertStatus {
   peer?: CertInfo
 }
 
-function statusTag(s: HANode['status']) {
+function statusTag(s: HANode['status'], t: (k: string) => string) {
   switch (s) {
-    case 'online':  return <Tag color="green">online</Tag>
-    case 'offline': return <Tag color="red">offline</Tag>
-    case 'joining': return <Tag color="blue">joining</Tag>
-    case 'leaving': return <Tag color="orange">leaving</Tag>
-    default:        return <Tag>unknown</Tag>
+    case 'online':  return <Tag color="green">{t('cluster.status.online')}</Tag>
+    case 'offline': return <Tag color="red">{t('cluster.status.offline')}</Tag>
+    case 'joining': return <Tag color="blue">{t('cluster.status.joining')}</Tag>
+    case 'leaving': return <Tag color="orange">{t('cluster.status.leaving')}</Tag>
+    default:        return <Tag>{t('cluster.status.unknown')}</Tag>
   }
 }
 
@@ -208,7 +208,7 @@ export default function ClusterPage() {
     },
     {
       title: t('cluster.col.status'), dataIndex: 'status', width: 110,
-      render: (s: HANode['status']) => statusTag(s),
+      render: (s: HANode['status']) => statusTag(s, t),
     },
     { title: t('cluster.col.role'), dataIndex: 'role', width: 110,
       render: (v: string) => <Tag color={v === 'primary' ? 'gold' : 'default'}>{v}</Tag> },
@@ -324,7 +324,7 @@ export default function ClusterPage() {
               </Space>
             </Descriptions.Item>
             <Descriptions.Item label={t('cluster.col.status')}>
-              {statusTag(data.local_node.status)}
+              {statusTag(data.local_node.status, t)}
             </Descriptions.Item>
             <Descriptions.Item label={t('cluster.col.role')}>
               <Tag color={data.local_node.role === 'primary' ? 'gold' : 'default'}>

management-ui/src/pages/Users/index.tsx

@@ -91,7 +91,7 @@ export default function UsersPage() {
       render: (s: string) => (
         <Space size={6}>
           <span>{s}</span>
-          {me?.actor === s && <Tag style={{ fontSize: 11, padding: '0 4px' }}>You</Tag>}
+          {me?.actor === s && <Tag style={{ fontSize: 11, padding: '0 4px' }}>{t('users.you')}</Tag>}
         </Space>
       ),
     },