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.AuditLog.Tests/Site/FallbackAuditWriterTests.cs

@@ -10,7 +10,7 @@ using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
 namespace ZB.MOM.WW.ScadaBridge.AuditLog.Tests.Site;
 
 /// <summary>
-/// Bundle B (M2-T4) tests for <see cref="FallbackAuditWriter"/> — composes the
+/// Tests for <see cref="FallbackAuditWriter"/> — composes the
 /// primary <see cref="SqliteAuditWriter"/>, the drop-oldest
 /// <see cref="RingBufferFallback"/>, and an
 /// <see cref="IAuditWriteFailureCounter"/> health counter.
@@ -28,9 +28,12 @@ public class FallbackAuditWriterTests
     /// <summary>Flip-switch primary writer mock.</summary>
     private sealed class FlipSwitchPrimary : IAuditWriter
     {
+        /// <summary>Gets or sets a value indicating whether the next write fails.</summary>
         public bool FailNext { get; set; }
+        /// <summary>Gets the events the primary has accepted.</summary>
         public List<AuditEvent> Written { get; } = new();
 
+        /// <inheritdoc />
         public Task WriteAsync(AuditEvent evt, CancellationToken ct = default)
         {
             if (FailNext)
@@ -42,6 +45,8 @@ public class FallbackAuditWriterTests
         }
     }
 
+    /// <summary>Verifies that when the primary writer throws, the event lands in the ring buffer and the call still returns successfully.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task WriteAsync_PrimaryThrows_EventLandsInRing_CallReturnsSuccess()
     {
@@ -59,6 +64,8 @@ public class FallbackAuditWriterTests
         counter.Received(1).Increment();
     }
 
+    /// <summary>Verifies that after the primary recovers, the ring buffer drains in FIFO order on the next write.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task WriteAsync_PrimaryRecovers_RingDrains_InFIFOOrder_OnNextWrite()
     {
@@ -93,6 +100,8 @@ public class FallbackAuditWriterTests
         Assert.Equal("c", primary.Written[3].Target);
     }
 
+    /// <summary>Verifies that the ring buffer stays empty when the primary writer always succeeds.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task WriteAsync_PrimaryAlwaysSucceeds_Ring_StaysEmpty()
     {
@@ -112,6 +121,8 @@ public class FallbackAuditWriterTests
         counter.DidNotReceive().Increment();
     }
 
+    /// <summary>Verifies that the failure counter is incremented once per primary failure.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task WriteAsync_FailureCounter_Incremented_Per_PrimaryFailure()
     {