fix(i18n): backfill missing admin.ldap translation keys

The admin.ldap message block referenced throughout the LDAP admin
page (t('title'), t('connectionTitle'), t('serverUrl'), field-mapping
and sync labels, etc.) didn't exist in de.json/en.json at all, so the
whole page rendered raw translation keys instead of text -- a
pre-existing gap surfaced while testing the new AD-prefill/group-filter
feature on this same page.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/src/messages/en.json

@@ -280,7 +280,38 @@
       "cannotDeleteActive": "Cannot delete tenants with active users"
     },
     "ldap": {
+      "title": "LDAP configuration",
+      "connectionTitle": "Connection settings",
+      "serverUrl": "Server URL",
+      "baseDn": "Base DN",
+      "bindDn": "Bind DN",
+      "bindPassword": "Bind password",
+      "searchFilter": "Search filter",
+      "save": "Save",
+      "testConnection": "Test connection",
+      "testSuccess": "Connection successful",
+      "testFailed": "Connection failed",
+      "enable": "Enabled",
+      "disable": "Disabled",
       "bindDnHint": "AD format: domain\\username (e.g. ctl\\serviceaccount), not DN notation.",
+      "fieldMapping": {
+        "title": "Field mapping",
+        "add": "Add mapping",
+        "ldapField": "LDAP field",
+        "tesseraField": "Tessera field",
+        "default": "Default",
+        "remove": "Remove"
+      },
+      "sync": {
+        "title": "Synchronization",
+        "interval": "Sync interval",
+        "intervalDisabled": "disabled",
+        "lastSync": "Last sync",
+        "neverSynced": "Never synced",
+        "trigger": "Sync now",
+        "syncing": "Syncing...",
+        "result": "Created: {created}, updated: {updated}, deactivated: {deactivated}"
+      },
       "groupFilter": {
         "title": "Import filter (groups/OUs)",
         "description": "Restrict sync to selected AD groups or organizational units. With no selection, every user under the base DN is imported.",