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/Pickers/ModbusAddressBuilderTests.cs

@@ -6,6 +6,11 @@ namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Pickers;
 
 public sealed class ModbusAddressBuilderTests
 {
+    /// <summary>Verifies that Build produces canonical Modbus address strings for all supported register types.</summary>
+    /// <param name="type">The Modbus register type.</param>
+    /// <param name="offset">The register offset.</param>
+    /// <param name="length">The data length.</param>
+    /// <param name="expected">The expected canonical address string.</param>
     [Theory]
     [InlineData("Holding", 1, 1, "4x00001-1")]
     [InlineData("Coil", 0, 1, "0x00000-1")]
@@ -15,6 +20,7 @@ public sealed class ModbusAddressBuilderTests
     public void Build_Canonical(string type, int offset, int length, string expected)
         => ModbusAddressBuilder.Build(type, offset, length).ShouldBe(expected);
 
+    /// <summary>Verifies that Build falls back to the Holding register type for unknown type strings.</summary>
     [Fact]
     public void Build_UnknownType_FallsBackToHolding()
         => ModbusAddressBuilder.Build("Unknown", 1, 1).ShouldBe("4x00001-1");