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.Health/tests/ZB.MOM.WW.Health.Akka.Tests/AkkaClusterStatusPolicyTests.cs

@@ -1,3 +1,4 @@
+using Akka.Actor;
 using Akka.Cluster;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
@@ -70,6 +71,30 @@ public sealed class AkkaClusterStatusPolicyTests
         Assert.Equal(HealthStatus.Degraded, result.Status);
     }
 
+    [Fact]
+    public async Task HealthCheck_ActorSystemPresentButClusterInaccessible_ReturnsDegraded()
+    {
+        // A plain (non-clustered) ActorSystem exists in DI, but Akka.Cluster is not configured,
+        // so Cluster.Get(system) throws a ConfigurationException — the startup race the spec calls
+        // out. The check must return Degraded, not let the exception escape (→ Unhealthy via the host).
+        using var system = ActorSystem.Create("plain-no-cluster");
+        try
+        {
+            var provider = new ServiceCollection()
+                .AddSingleton(system)
+                .BuildServiceProvider();
+            var check = new AkkaClusterHealthCheck(provider, AkkaClusterStatusPolicy.Default);
+
+            var result = await check.CheckHealthAsync(NewContext(check));
+
+            Assert.Equal(HealthStatus.Degraded, result.Status);
+        }
+        finally
+        {
+            await system.Terminate();
+        }
+    }
+
     private static HealthCheckContext NewContext(IHealthCheck check) => new()
     {
         Registration = new HealthCheckRegistration("akka-cluster", check, HealthStatus.Unhealthy, tags: null),