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/Client/ZB.MOM.WW.OtOpcUa.Client.CLI.Tests/WriteCommandTests.cs

@@ -9,6 +9,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;
 public class WriteCommandTests
 {
     /// <summary>Verifies that write command executes successfully.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Execute_WritesSuccessfully()
     {
@@ -33,6 +34,7 @@ public class WriteCommandTests
     }
 
     /// <summary>Verifies that write command reports failure.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Execute_ReportsFailure()
     {
@@ -57,6 +59,7 @@ public class WriteCommandTests
     }
 
     /// <summary>Verifies that write command reads current value before writing.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Execute_ReadsCurrentValueThenWrites()
     {
@@ -83,6 +86,7 @@ public class WriteCommandTests
     }
 
     /// <summary>Verifies that write command disconnects in finally block.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Execute_DisconnectsInFinally()
     {