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/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ModbusCoalescingBisectionTests.cs

@@ -22,15 +22,9 @@ public sealed class ModbusCoalescingBisectionTests
     {
         /// <summary>Gets or sets the protected address that will cause read failures.</summary>
         public ushort ProtectedAddress { get; set; } = ushort.MaxValue;
-        /// <summary>Simulates connecting to the Modbus device.</summary>
-        /// <param name="ct">The cancellation token.</param>
-        /// <returns>A completed task.</returns>
+        /// <inheritdoc />
         public Task ConnectAsync(CancellationToken ct) => Task.CompletedTask;
-        /// <summary>Simulates sending a Modbus PDU and failing if the protected address is accessed.</summary>
-        /// <param name="unitId">The Modbus unit ID.</param>
-        /// <param name="pdu">The protocol data unit.</param>
-        /// <param name="ct">The cancellation token.</param>
-        /// <returns>The response PDU or an exception if the protected address is accessed.</returns>
+        /// <inheritdoc />
         public Task<byte[]> SendAsync(byte unitId, byte[] pdu, CancellationToken ct)
         {
             var addr = (ushort)((pdu[1] << 8) | pdu[2]);
@@ -54,6 +48,7 @@ public sealed class ModbusCoalescingBisectionTests
     }
 
     /// <summary>Verifies that bisection narrows a multi-register prohibition on each reprobe cycle.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Bisection_Narrows_Multi_Register_Prohibition_Per_Reprobe()
     {
@@ -98,6 +93,7 @@ public sealed class ModbusCoalescingBisectionTests
     }
 
     /// <summary>Verifies that the prohibition is cleared when both bisected halves succeed in recovery.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Bisection_Clears_When_Both_Halves_Are_Healthy()
     {
@@ -127,6 +123,7 @@ public sealed class ModbusCoalescingBisectionTests
     }
 
     /// <summary>Verifies that the prohibition splits into two entries when both bisected halves still fail.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Bisection_Splits_Into_Two_When_Both_Halves_Still_Fail()
     {
@@ -160,15 +157,9 @@ public sealed class ModbusCoalescingBisectionTests
     private sealed class TwoHoleTransport : IModbusTransport
     {
         public readonly HashSet<ushort> ProtectedAddresses = new();
-        /// <summary>Simulates connecting to the Modbus device.</summary>
-        /// <param name="ct">The cancellation token.</param>
-        /// <returns>A completed task.</returns>
+        /// <inheritdoc />
         public Task ConnectAsync(CancellationToken ct) => Task.CompletedTask;
-        /// <summary>Simulates sending a Modbus PDU and failing if any protected address is accessed.</summary>
-        /// <param name="unitId">The Modbus unit ID.</param>
-        /// <param name="pdu">The protocol data unit.</param>
-        /// <param name="ct">The cancellation token.</param>
-        /// <returns>The response PDU or an exception if a protected address is accessed.</returns>
+        /// <inheritdoc />
         public Task<byte[]> SendAsync(byte unitId, byte[] pdu, CancellationToken ct)
         {
             var addr = (ushort)((pdu[1] << 8) | pdu[2]);