feat(260728-lih): default LDAP create-form syncIntervalMin to 0 + reword copy

- New-config create form now defaults syncIntervalMin to 0 (matches
  backend default, auto-sync off by default)
- de+en groupFilter.description + emptyMeansAll reworded: empty
  selection now says "nothing is synced" instead of "imports everyone
  under the base DN" (matches the backend semantic change)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/web/src/app/(portal)/admin/ldap/page.tsx

@@ -84,7 +84,7 @@ export default function AdminLdapPage() {
     bindDn: '',
     bindPassword: '',
     searchFilter: '(objectClass=person)',
-    syncIntervalMin: 60,
+    syncIntervalMin: 0,
     isActive: true,
     tlsRejectUnauthorized: true,
   });

apps/web/src/messages/de.json

@@ -317,7 +317,7 @@
       },
       "groupFilter": {
         "title": "Import-Filter (Gruppen/OUs)",
-        "description": "Beschraenkt den Sync auf ausgewaehlte AD-Gruppen oder Organisationseinheiten. Ohne Auswahl werden alle Benutzer unter der Basis-DN importiert.",
+        "description": "Beschraenkt den Sync auf ausgewaehlte AD-Gruppen oder Organisationseinheiten. Ohne Auswahl wird nichts synchronisiert.",
         "discover": "Gruppen/OUs suchen",
         "typeOu": "OU",
         "typeGroup": "Gruppe",
@@ -327,7 +327,7 @@
         "manualDn": "DN manuell hinzufuegen",
         "addDn": "Hinzufuegen",
         "selected": "Ausgewaehlt",
-        "emptyMeansAll": "Keine Auswahl - importiert alle Benutzer unter der Basis-DN.",
+        "emptyMeansAll": "Keine Auswahl - es wird nichts synchronisiert.",
         "save": "Filter speichern"
       },
       "userExclude": {

apps/web/src/messages/en.json

@@ -317,7 +317,7 @@
       },
       "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.",
+        "description": "Restrict sync to selected AD groups or organizational units. With no selection, nothing is synced.",
         "discover": "Discover groups/OUs",
         "typeOu": "OU",
         "typeGroup": "Group",
@@ -327,7 +327,7 @@
         "manualDn": "Add DN manually",
         "addDn": "Add",
         "selected": "Selected",
-        "emptyMeansAll": "No selection - imports every user under the base DN.",
+        "emptyMeansAll": "No selection - nothing is synced.",
         "save": "Save filter"
       },
       "userExclude": {