fix: bind OtOpcUa LdapOptions from real Security:Ldap section; gate validator on DevStubMode

src/Server/ZB.MOM.WW.OtOpcUa.Security/Ldap/LdapOptions.cs

@@ -2,12 +2,12 @@ namespace ZB.MOM.WW.OtOpcUa.Security.Ldap;
 
 /// <summary>
 ///     LDAP + role-mapping configuration for the Admin UI. Bound from <c>appsettings.json</c>
-///     <c>Authentication:Ldap</c> section. Defaults point at the local GLAuth dev instance (see
+///     <c>Security:Ldap</c> section. Defaults point at the local GLAuth dev instance (see
 ///     <c>C:\publish\glauth\auth.md</c>).
 /// </summary>
 public sealed class LdapOptions
 {
-    public const string SectionName = "Authentication:Ldap";
+    public const string SectionName = "Security:Ldap";
 
     /// <summary>Gets or sets a value indicating whether LDAP authentication is enabled.</summary>
     public bool Enabled { get; set; } = true;