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.TemplateEngine.Tests/Flattening/FlatteningServiceMergeTests.cs

@@ -12,6 +12,7 @@ public class FlatteningServiceMergeTests
 {
     // ── MergeHiLoConfig ────────────────────────────────────────────────────
 
+    /// <summary>Verifies that merging prefers derived keys while inherited keys that are not overridden survive.</summary>
     [Fact]
     public void MergeHiLoConfig_DerivedKeysWin_InheritedKeysSurvive()
     {
@@ -29,6 +30,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal(100, doc.RootElement.GetProperty("hiHi").GetDouble()); // inherited
     }
 
+    /// <summary>Verifies that a derived config can override the attribute name.</summary>
     [Fact]
     public void MergeHiLoConfig_DerivedCanOverrideAttribute()
     {
@@ -42,6 +44,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal(50, doc.RootElement.GetProperty("hi").GetDouble());
     }
 
+    /// <summary>Verifies that merging returns the inherited config when the derived config is null.</summary>
     [Fact]
     public void MergeHiLoConfig_DerivedNull_ReturnsInherited()
     {
@@ -52,6 +55,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal(inherited, result);
     }
 
+    /// <summary>Verifies that merging returns the derived config when the inherited config is null.</summary>
     [Fact]
     public void MergeHiLoConfig_InheritedNull_ReturnsDerived()
     {
@@ -62,12 +66,14 @@ public class FlatteningServiceMergeTests
         Assert.Equal(derived, result);
     }
 
+    /// <summary>Verifies that merging returns null when both configs are null.</summary>
     [Fact]
     public void MergeHiLoConfig_BothNull_ReturnsNull()
     {
         Assert.Null(FlatteningService.MergeHiLoConfig(null, null));
     }
 
+    /// <summary>Verifies that merging falls back to the derived config when the inherited config is malformed.</summary>
     [Fact]
     public void MergeHiLoConfig_MalformedInherited_FallsBackToDerived()
     {
@@ -79,6 +85,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal(derived, result);
     }
 
+    /// <summary>Verifies that a new derived key is added while the remaining inherited keys are preserved.</summary>
     [Fact]
     public void MergeHiLoConfig_DerivedAddsNewKey_PreservesInheritedRest()
     {
@@ -96,6 +103,7 @@ public class FlatteningServiceMergeTests
 
     // ── DiffHiLoConfig ─────────────────────────────────────────────────────
 
+    /// <summary>Verifies that diffing identical configs returns null.</summary>
     [Fact]
     public void DiffHiLoConfig_NoChanges_ReturnsNull()
     {
@@ -103,6 +111,7 @@ public class FlatteningServiceMergeTests
         Assert.Null(FlatteningService.DiffHiLoConfig(both, both));
     }
 
+    /// <summary>Verifies that diffing returns only the key that changed.</summary>
     [Fact]
     public void DiffHiLoConfig_ChangedKey_ReturnsOnlyChangedKey()
     {
@@ -118,6 +127,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal(90, prop.Value.GetDouble());
     }
 
+    /// <summary>Verifies that a newly added key appears in the diff.</summary>
     [Fact]
     public void DiffHiLoConfig_NewKey_AddedToDiff()
     {
@@ -132,6 +142,7 @@ public class FlatteningServiceMergeTests
         Assert.False(doc.RootElement.TryGetProperty("hi", out _));
     }
 
+    /// <summary>Verifies that diffing against a null inherited config returns the edited config verbatim.</summary>
     [Fact]
     public void DiffHiLoConfig_NullInherited_ReturnsEditedVerbatim()
     {
@@ -139,12 +150,14 @@ public class FlatteningServiceMergeTests
         Assert.Equal(edited, FlatteningService.DiffHiLoConfig(null, edited));
     }
 
+    /// <summary>Verifies that diffing a null edited config returns null.</summary>
     [Fact]
     public void DiffHiLoConfig_NullEdited_ReturnsNull()
     {
         Assert.Null(FlatteningService.DiffHiLoConfig(@"{""hi"":80}", null));
     }
 
+    /// <summary>Verifies that diffing ignores differences in string escaping.</summary>
     [Fact]
     public void DiffHiLoConfig_IgnoresStringEscapeDifferences()
     {
@@ -158,6 +171,7 @@ public class FlatteningServiceMergeTests
         Assert.Null(diff); // no real change once values are decoded
     }
 
+    /// <summary>Verifies that diffing ignores differences in numeric formatting.</summary>
     [Fact]
     public void DiffHiLoConfig_IgnoresNumericFormatDifferences()
     {
@@ -167,6 +181,7 @@ public class FlatteningServiceMergeTests
         Assert.Null(FlatteningService.DiffHiLoConfig(inherited, edited));
     }
 
+    /// <summary>Verifies that a diff merged back onto the inherited config reproduces the edited config.</summary>
     [Fact]
     public void DiffHiLoConfig_RoundTripsThroughMerge()
     {
@@ -227,6 +242,7 @@ public class FlatteningServiceMergeTests
         return result.Value!;
     }
 
+    /// <summary>Verifies that an instance alarm override merges its high/low setpoints into the flattened alarm.</summary>
     [Fact]
     public void Flatten_InstanceAlarmOverride_HiLo_MergesSetpoints()
     {
@@ -250,6 +266,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal("Override", alarm.Source);
     }
 
+    /// <summary>Verifies that an instance alarm override replaces the alarm priority.</summary>
     [Fact]
     public void Flatten_InstanceAlarmOverride_OverridesPriority()
     {
@@ -268,6 +285,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal("Override", alarm.Source);
     }
 
+    /// <summary>Verifies that an override targeting a locked alarm is silently ignored.</summary>
     [Fact]
     public void Flatten_InstanceAlarmOverride_LockedAlarm_OverrideSilentlyIgnored()
     {
@@ -291,6 +309,7 @@ public class FlatteningServiceMergeTests
         Assert.Equal(80, doc.RootElement.GetProperty("hi").GetDouble()); // not overridden
     }
 
+    /// <summary>Verifies that an override naming an unknown alarm has no effect.</summary>
     [Fact]
     public void Flatten_InstanceAlarmOverride_UnknownName_DoesNothing()
     {
@@ -312,6 +331,7 @@ public class FlatteningServiceMergeTests
         Assert.NotEqual("Override", alarm.Source);
     }
 
+    /// <summary>Verifies that an override on a binary-trigger alarm replaces the whole trigger config.</summary>
     [Fact]
     public void Flatten_InstanceAlarmOverride_BinaryTrigger_ReplacesWholeConfig()
     {