chore(deps): move every ZB.MOM.WW pin to the newest published version

Auth 0.1.5 -> 0.2.0, Health 0.2.0 -> 0.3.0, Secrets/.Abstractions/.Ui
0.6.1 -> 0.6.2. Theme, GalaxyRepository, Audit, Configuration, Telemetry
and Telemetry.Serilog were already at the newest version on the feed.

Checked against the shared-lib source rather than the version numbers,
because these packages are versioned as a family and a bump is not by
itself evidence that the package changed:

- Auth 0.2.0 is the only one carrying content for us: LDAP backup-DC
  failover (FallbackServers, endpoint walk with sticky preference,
  boot-time entry validation). Purely additive; the default is empty,
  which leaves single-endpoint behaviour unchanged.
- Health 0.3.0 carries a breaking change, but every line of it is in
  ZB.MOM.WW.Health.Akka, which we do not reference. No commit touched
  the core ZB.MOM.WW.Health package between 0.2.0 and 0.3.0.
- Secrets 0.6.2 is a message-only change: one validator string literal
  gains mounted-volume guidance. SecretsStorePathRules is untouched.

The four non-csproj files are not a separate feature. Configuration/
LdapOptions is a deliberate shadow of the shared type and carries an
explicit warning to mirror any new upstream field, because AddZbLdapAuth
binds the whole MxGateway:Ldap section onto the shared options. So
FallbackServers is live on our config surface the moment the package
lands, and without the mirror an operator could configure a backup DC
that works but is invisible on the dashboard's Settings page. The
Settings row renders "none" when empty, since that is the answer someone
who believes a backup DC is configured actually needs.

Entry syntax is deliberately NOT re-validated here: the shared validator
already fails the boot on a malformed entry and owns the (internal)
parser, so a second copy would drift. Note both validators skip entirely
when Ldap:Enabled is false.

Verified the binder is non-strict (ErrorOnUnknownConfiguration is unused
anywhere in the tree), so the upgrade could not break startup on a
newly-recognised key either way.

Build 0 warnings / 0 errors; gateway suite 892/892, unchanged. The live
LDAP tests are opt-in and were not run, so the failover path itself is
covered only by the shared library's own tests.

src/ZB.MOM.WW.MxGateway.Server/Configuration/LdapOptions.cs

@@ -68,4 +68,19 @@ public sealed class LdapOptions
 
     /// <summary>Gets the LDAP attribute name for group membership.</summary>
     public string GroupAttribute { get; init; } = "memberOf";
+
+    /// <summary>
+    /// Gets the ordered fallback LDAP endpoints (<c>"host"</c> or <c>"host:port"</c>) the shared
+    /// provider walks when the primary fails with a system-side error. Empty (the default) leaves
+    /// single-endpoint behaviour unchanged. Mirrors
+    /// <see cref="ZB.MOM.WW.Auth.Abstractions.Ldap.LdapOptions.FallbackServers"/>, added in
+    /// ZB.MOM.WW.Auth 0.2.0.
+    /// <para>
+    /// Carried here only so the effective-config display does not hide a configured backup DC —
+    /// nothing on the gateway side reads it. Entry syntax is validated at boot by the shared
+    /// <c>LdapOptionsValidator</c>, which owns the (internal) parser; re-validating here would
+    /// mean a second, drifting copy of that grammar.
+    /// </para>
+    /// </summary>
+    public IReadOnlyList<string> FallbackServers { get; init; } = [];
 }