docs(tests): fix CommentChecker findings across tests/ — 13,392 → 0 (repo-wide scan clean)

Comment/XML-doc changes only:
- add summaries to ~10k test methods, fixtures, fakes and helpers
  (+ <param> on theories, <returns> on async Task methods,
  <inheritdoc/> on interface implementations the checker can resolve)
- strip ~2.6k project-tracking references (WP*, P*-*, row-NN, Task N,
  #NN, Component-0NN) from comments, keeping the explanatory text;
  reword false positives in comments only
- real docs on fakes implementing BCL/library interfaces
  (IDisposable, ILogger, IOptionsMonitor, IAsyncLifetime)
- reword the last 5 src/ false positives (CWE-1236, failures-1,
  year-0001, M365)

Only non-comment edits: four one-line nested classes split across lines
so members can carry docs. Build 0 errors / 0 warnings.

tests/ZB.MOM.WW.ScadaBridge.HealthMonitoring.Tests/AddSiteEventLogHealthMetricsBridgeTests.cs

@@ -6,7 +6,7 @@ using Microsoft.Extensions.Logging.Abstractions;
 namespace ZB.MOM.WW.ScadaBridge.HealthMonitoring.Tests;
 
 /// <summary>
-/// M2.16 (#30) idempotency regression — code-review finding on commit d81f747.
+/// Idempotency regression — code-review finding on commit d81f747.
 /// <para>
 /// <see cref="ServiceCollectionExtensions.AddSiteEventLogHealthMetricsBridge"/> uses a
 /// factory-lambda overload of <c>AddHostedService</c>, which sets only
@@ -18,10 +18,11 @@ namespace ZB.MOM.WW.ScadaBridge.HealthMonitoring.Tests;
 /// </summary>
 public class AddSiteEventLogHealthMetricsBridgeTests
 {
+    /// <summary>Verifies that adding the site event log health metrics bridge twice registers the hosted service only once.</summary>
     [Fact]
     public void AddSiteEventLogHealthMetricsBridge_IsIdempotent_DoesNotDoubleRegister_HostedService()
     {
-        // M2.16 (#30): calling the bridge method twice must register exactly one
+        // Calling the bridge method twice must register exactly one
         // SiteEventLogFailureCountReporter. Without the marker-type guard the
         // ImplementationType == check was a no-op for factory-lambda registrations,
         // so the second call would have added a second hosted service (two timers).