Fix all baseline code-review findings across the six shared libraries

Resolves the 35 findings from the 2026-06-01 baseline (commit 26ba1c7),
test-first for every behavioral change. +51 tests (331 -> 382 passing, 0 failed).

- Telemetry-001 (HIGH): RedactionEnricher now honours property removal, so a
  redactor that drops a key actually scrubs the secret from the event.
- Auth: LDAP validator ValidateOnStart; API-key verify no longer fails on a
  best-effort MarkUsed write or a corrupt scopes column (fail-closed); LDAP cert
  validation hook; KeyPrefix persistence aligned; README algorithm corrected.
- Health: Akka checks return Degraded (not throw) when the cluster isn't up yet;
  GrpcDependencyHealthCheck catch-all; null 'description' rendered; composite
  endpoint builder; XML docs shipped.
- Audit: CompositeAuditWriter no longer re-throws OperationCanceledException;
  TruncatingAuditRedactor over-redact scrubs Target + safe negative max; options
  record; XML docs shipped.
- Configuration: TryAddEnumerable idempotent registration; consistent port
  quoting; strict invariant port parsing; XML docs + README packaged.
- Theme: mobile toggle is now CSS-only (no Bootstrap JS); token/CSS hygiene;
  XML docs on the public parameter surface.

Shared-contract/spec docs updated where the code was the source of truth
(observability service.instance.id, MapZbMetrics, redactor reach). All changes
additive/back-compatible at v0.1.0. code-reviews bookkeeping follows separately.

ZB.MOM.WW.Auth/tests/ZB.MOM.WW.Auth.Ldap.Tests/FakeLdapConnection.cs

@@ -1,3 +1,4 @@
+using System.Net.Security;
 using ZB.MOM.WW.Auth.Abstractions.Ldap;
 using ZB.MOM.WW.Auth.Ldap.Internal;
 
@@ -19,6 +20,10 @@ internal sealed class FakeLdapConnection : ILdapConnection
     // ---- observation -----
 
     public (string Host, int Port, LdapTransport Transport, bool AllowInsecure, int TimeoutMs)? ConnectArgs { get; private set; }
+
+    /// <summary>The server-certificate validation callback passed to the most recent <see cref="Connect"/> call.</summary>
+    public RemoteCertificateValidationCallback? ConnectCertCallback { get; private set; }
+
     public List<string> BoundDns { get; } = new();
 
     /// <summary>
@@ -107,9 +112,16 @@ internal sealed class FakeLdapConnection : ILdapConnection
 
     // ---- ILdapConnection -----
 
-    public void Connect(string host, int port, LdapTransport transport, bool allowInsecure, int timeoutMs)
+    public void Connect(
+        string host,
+        int port,
+        LdapTransport transport,
+        bool allowInsecure,
+        int timeoutMs,
+        RemoteCertificateValidationCallback? serverCertificateValidationCallback = null)
     {
         ConnectArgs = (host, port, transport, allowInsecure, timeoutMs);
+        ConnectCertCallback = serverCertificateValidationCallback;
         if (_throwOnConnect)
             throw new Novell.Directory.Ldap.LdapException(
                 "Directory unreachable", Novell.Directory.Ldap.LdapException.ConnectError, host);