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/AbLegacyDriverPageFormSerializationTests.cs

@@ -22,6 +22,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
     };
 
+    /// <summary>Verifies that round-trip serialization preserves all known fields.</summary>
     [Fact]
     public void RoundTrip_PreservesKnownFields()
     {
@@ -71,6 +72,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         back.Tags[1].DataType.ShouldBe(AbLegacyDataType.Bit);
     }
 
+    /// <summary>Verifies that deserialization silently drops unknown fields.</summary>
     [Fact]
     public void Deserialize_DropsUnknownFields()
     {
@@ -86,6 +88,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         back.ProbeTimeoutSeconds.ShouldBe(10);
     }
 
+    /// <summary>Verifies that a device row round-trips through its definition.</summary>
     [Fact]
     public void DeviceRow_round_trips_through_definition()
     {
@@ -101,6 +104,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         back.DeviceName.ShouldBe("PLC-A");
     }
 
+    /// <summary>Verifies that a device row preserves unedited fields when converting back to definition.</summary>
     [Fact]
     public void DeviceRow_preserves_unedited_fields()
     {
@@ -114,6 +118,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         back.DeviceName.ShouldBe("PLC-A");
     }
 
+    /// <summary>Verifies that a tag row round-trips through its definition.</summary>
     [Fact]
     public void TagRow_round_trips_through_definition()
     {
@@ -132,6 +137,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         back.Writable.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that a tag row preserves unedited fields when converting back to definition.</summary>
     [Fact]
     public void TagRow_preserves_unedited_fields()
     {
@@ -146,6 +152,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
         back.WriteIdempotent.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that device row validation rejects a duplicate host address.</summary>
     [Fact]
     public void ValidateDeviceRow_rejects_duplicate_host()
     {
@@ -154,6 +161,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
             .ShouldNotBeNull();
     }
 
+    /// <summary>Verifies that tag row validation rejects a duplicate tag name.</summary>
     [Fact]
     public void ValidateTagRow_rejects_duplicate_name()
     {
@@ -162,6 +170,7 @@ public sealed class AbLegacyDriverPageFormSerializationTests
             .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()
     {