fix(i18n): RemoteTargets S3/SFTP-Labels + NTP-Interface-Labels vollständig lokalisieren

RemoteTargets: alle 20+ hardkodierten Form-Labels und deutschen Hilfetexte
(S3: Endpoint/Region/Bucket/AccessKey/SecretKey/PathPrefix/HTTPS;
 SFTP: Host/Port/Username/Password/PrivateKey/RemoteDir/HostKeyFp)
sind jetzt in t()-Aufrufen mit remotes.s3.*/remotes.sftp.*-Keys.

NTP: Listen-Address-Dropdown-Labels (alle IPv4/IPv6-Interfaces, Loopback)
verwenden jetzt dns.settings.allIPv4/allIPv6/loopback (identisch zu DNS-Settings).
NTP-Pool-Adresse-Placeholder → t('ntp.pool.addressPlaceholder').

en/de: alle neuen Keys ergänzt.

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

management-ui/src/i18n/locales/en/common.json

@@ -806,6 +806,7 @@
       "kindServer": "server — single host",
       "address": "Address / host",
       "addressExtra": "FQDN (for pool: 0.de.pool.ntp.org) or IP.",
+      "addressPlaceholder": "0.de.pool.ntp.org or 10.0.0.10",
       "iburst": "iburst",
       "prefer": "prefer",
       "minpoll": "min-poll",
@@ -1090,6 +1091,34 @@
     "testFailed": "Test failed",
     "confirmDelete": "Really delete target {{name}}?",
     "targetExtra": "Free-text label for the overview. Use bucket/path hint (s3://my-bucket or sftp://backup@host).",
+    "namePlaceholder": "e.g. MinIO offsite / Hetzner Storage Box",
+    "kindS3": "S3 (AWS / MinIO / R2 / B2 / Hetzner Object)",
+    "kindSftp": "SFTP (SSH)",
+    "s3": {
+      "endpoint": "Endpoint",
+      "endpointExtra": "s3.amazonaws.com / minio.example.com:9000 / fsn1.your-objectstorage.com",
+      "region": "Region",
+      "regionPlaceholder": "eu-central-1 / auto (R2)",
+      "bucket": "Bucket",
+      "accessKey": "Access Key",
+      "secretKey": "Secret Key",
+      "pathPrefix": "Path Prefix",
+      "pathPrefixExtra": "e.g. edgeguard/utm-1 — prepended to every filename",
+      "useSsl": "HTTPS (use_ssl)"
+    },
+    "sftp": {
+      "host": "Host",
+      "port": "Port",
+      "username": "Username",
+      "password": "Password",
+      "passwordExtra": "Either password OR private key.",
+      "privateKey": "Private Key (OpenSSH, base64)",
+      "privateKeyPlaceholder": "base64-encoded OpenSSH private key",
+      "remoteDir": "Remote Dir",
+      "remoteDirExtra": "e.g. /backups/edgeguard",
+      "hostKeyFp": "Host Key Fingerprint",
+      "hostKeyFpExtra": "Optional. SHA256:... — leave empty for TOFU (insecure against MitM)"
+    },
     "col": {
       "name": "Name",
       "kind": "Kind",