docs: complete XML doc comments via fixdocs (2757 to 131 findings)

Add missing <returns>/<param>/<summary>/<typeparam> tags and clean up
misused inheritdoc across 481 files so the documented API surface is
complete. Documentation-only (zero code lines changed). The 131 remaining
findings are inheritdoc-style warnings deliberately left to preserve
hand-written implementation rationale (plan-decision notes, race-condition
explanations).

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/FocasDriverPageFormSerializationTests.cs

@@ -21,6 +21,7 @@ public sealed class FocasDriverPageFormSerializationTests
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
     };
 
+    /// <summary>Verifies that a round-trip serialization preserves all known FOCAS driver option fields.</summary>
     [Fact]
     public void RoundTrip_PreservesKnownFields()
     {
@@ -76,6 +77,7 @@ public sealed class FocasDriverPageFormSerializationTests
         back.Tags.ShouldBeEmpty();
     }
 
+    /// <summary>Verifies that deserialization silently drops unknown fields without throwing.</summary>
     [Fact]
     public void Deserialize_DropsUnknownFields()
     {
@@ -89,6 +91,7 @@ public sealed class FocasDriverPageFormSerializationTests
         back.ProbeTimeoutSeconds.ShouldBe(18);
     }
 
+    /// <summary>Verifies that the form model round-trip preserves all editable FOCAS driver option fields.</summary>
     [Fact]
     public void FormModel_RoundTrip_PreservesEditableFields()
     {
@@ -140,6 +143,7 @@ public sealed class FocasDriverPageFormSerializationTests
         roundTripped.FixedTree.TimerPollInterval.ShouldBe(TimeSpan.FromSeconds(45));
     }
 
+    /// <summary>Verifies that a FocasDeviceRow round-trips correctly through its definition type.</summary>
     [Fact]
     public void DeviceRow_round_trips_through_definition()
     {
@@ -155,6 +159,7 @@ public sealed class FocasDriverPageFormSerializationTests
         back.DeviceName.ShouldBe("CNC1");
     }
 
+    /// <summary>Verifies that FocasDeviceRow preserves unedited fields when converting to and from a definition.</summary>
     [Fact]
     public void DeviceRow_preserves_unedited_fields()
     {
@@ -168,6 +173,7 @@ public sealed class FocasDriverPageFormSerializationTests
         back.Series.ShouldBe(FocasCncSeries.Thirty_i);
     }
 
+    /// <summary>Verifies that a FocasTagRow round-trips correctly through its definition type.</summary>
     [Fact]
     public void TagRow_round_trips_through_definition()
     {
@@ -186,6 +192,7 @@ public sealed class FocasDriverPageFormSerializationTests
         back.Writable.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that FocasTagRow preserves unedited fields when converting to a definition.</summary>
     [Fact]
     public void TagRow_preserves_unedited_fields()
     {
@@ -200,6 +207,7 @@ public sealed class FocasDriverPageFormSerializationTests
         back.WriteIdempotent.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that device row validation rejects a duplicate host address.</summary>
     [Fact]
     public void ValidateDeviceRow_rejects_duplicate_host()
     {
@@ -208,6 +216,7 @@ public sealed class FocasDriverPageFormSerializationTests
             .ShouldNotBeNull();
     }
 
+    /// <summary>Verifies that tag row validation rejects a duplicate tag name.</summary>
     [Fact]
     public void ValidateTagRow_rejects_duplicate_name()
     {
@@ -216,6 +225,7 @@ public sealed class FocasDriverPageFormSerializationTests
             .ShouldNotBeNull();
     }
 
+    /// <summary>Verifies that device and tag lists survive a full options serialization round-trip.</summary>
     [Fact]
     public void Device_and_tag_lists_survive_options_serialize_round_trip()
     {