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/Core/ZB.MOM.WW.OtOpcUa.Core.Scripting.Tests/TimedScriptEvaluatorTests.cs

@@ -14,6 +14,7 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Scripting.Tests;
 public sealed class TimedScriptEvaluatorTests
 {
     /// <summary>Verifies that fast scripts complete under timeout and return value.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Fast_script_completes_under_timeout_and_returns_value()
     {
@@ -28,6 +29,7 @@ public sealed class TimedScriptEvaluatorTests
     }
 
     /// <summary>Verifies that scripts longer than timeout throw ScriptTimeoutException.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Script_longer_than_timeout_throws_ScriptTimeoutException()
     {
@@ -50,6 +52,7 @@ public sealed class TimedScriptEvaluatorTests
     }
 
     /// <summary>Verifies that caller cancellation takes precedence over timeout.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Caller_cancellation_takes_precedence_over_timeout()
     {
@@ -108,6 +111,7 @@ public sealed class TimedScriptEvaluatorTests
     }
 
     /// <summary>Verifies that script exceptions propagate unwrapped.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Script_exception_propagates_unwrapped()
     {
@@ -124,6 +128,7 @@ public sealed class TimedScriptEvaluatorTests
     }
 
     /// <summary>Verifies that ScriptTimeoutException message points at diagnostic path.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ScriptTimeoutException_message_points_at_diagnostic_path()
     {
@@ -143,6 +148,7 @@ public sealed class TimedScriptEvaluatorTests
     }
 
     /// <summary>Verifies that caller cancellation wins even when timeout fires first.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Caller_cancellation_wins_even_when_timeout_fires_first()
     {