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.Commons.Tests/Observability/DataConnectionGaugeTests.cs

@@ -23,6 +23,7 @@ public sealed class DataConnectionGaugeTests
     private const string ConnectedGauge = "scadabridge.site.data_connections.connected";
     private const string TotalGauge = "scadabridge.site.data_connections.total";
 
+    /// <summary>Verifies that the connected state raises both the connected and total gauges.</summary>
     [Fact]
     public void ConnectedState_RaisesConnectedAndTotal()
     {
@@ -43,6 +44,8 @@ public sealed class DataConnectionGaugeTests
         }
     }
 
+    /// <summary>Verifies that a non-connected state raises only the total gauge.</summary>
+    /// <param name="state">The state.</param>
     [Theory]
     [InlineData(ConnectionHealth.Disconnected)]
     [InlineData(ConnectionHealth.Connecting)]
@@ -70,6 +73,7 @@ public sealed class DataConnectionGaugeTests
         }
     }
 
+    /// <summary>Verifies that a transition from connected to disconnected drops the connected gauge but keeps the total.</summary>
     [Fact]
     public void TransitionFromConnectedToDisconnected_DropsConnectedButKeepsTotal()
     {
@@ -94,6 +98,7 @@ public sealed class DataConnectionGaugeTests
         }
     }
 
+    /// <summary>Verifies that removing a data connection drops it from both gauges.</summary>
     [Fact]
     public void RemoveDataConnection_DropsItFromBothGauges()
     {
@@ -111,6 +116,7 @@ public sealed class DataConnectionGaugeTests
         Assert.Equal(totalBefore, ReadGauge(TotalGauge));
     }
 
+    /// <summary>Verifies that removing a data connection is idempotent.</summary>
     [Fact]
     public void RemoveDataConnection_IsIdempotent()
     {
@@ -123,6 +129,7 @@ public sealed class DataConnectionGaugeTests
         Assert.Null(ex);
     }
 
+    /// <summary>Verifies that a null or empty connection name is ignored.</summary>
     [Fact]
     public void NullOrEmptyConnectionName_IsIgnored()
     {
@@ -136,6 +143,7 @@ public sealed class DataConnectionGaugeTests
         Assert.Equal(totalBefore, ReadGauge(TotalGauge));
     }
 
+    /// <summary>Verifies that the stream subscriber gauge is published under its renamed name.</summary>
     [Fact]
     public void StreamSubscriberGauge_IsPublishedUnderTheRenamedName()
     {