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.Tests/GrpcDependencyHealthCheckTests.cs

@@ -71,6 +71,21 @@ public sealed class GrpcDependencyHealthCheckTests
         Assert.Contains("mxaccessgw worker", result.Description);
     }
 
+    [Fact]
+    public async Task ProbeThrowsArbitraryException_Unhealthy()
+    {
+        // A non-RpcException / non-OperationCanceledException (e.g. the transport surfacing an
+        // InvalidOperationException) must be caught and mapped to Unhealthy, not allowed to escape.
+        var result = await RunAsync(new GrpcDependencyOptions
+        {
+            DependencyName = "mxaccessgw worker",
+            Probe = static (_, _) => throw new InvalidOperationException("channel disposed"),
+        });
+
+        Assert.Equal(HealthStatus.Unhealthy, result.Status);
+        Assert.Contains("mxaccessgw worker", result.Description);
+    }
+
     [Fact]
     public async Task ProbeExceedsTimeout_Unhealthy()
     {