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.AbCip.Tests/AbCipLoggingTests.cs

@@ -36,6 +36,7 @@ public sealed class AbCipLoggingTests
     }
 
     /// <summary>Verifies that ProbeLoop logs when an exception is swallowed.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ProbeLoop_logs_when_an_exception_is_swallowed()
     {
@@ -79,6 +80,7 @@ public sealed class AbCipLoggingTests
     }
 
     /// <summary>Verifies that ReadFailure logs at warning level.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ReadFailure_logs_at_warning_level()
     {
@@ -106,6 +108,7 @@ public sealed class AbCipLoggingTests
     }
 
     /// <summary>Verifies that ReadException logs at warning level.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ReadException_logs_at_warning_level()
     {
@@ -137,6 +140,7 @@ public sealed class AbCipLoggingTests
     }
 
     /// <summary>Verifies that InitializeAsync warns when probe is enabled but ProbeTagPath is blank.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task InitializeAsync_warns_when_probe_is_enabled_but_ProbeTagPath_is_blank()
     {
@@ -164,6 +168,7 @@ public sealed class AbCipLoggingTests
     }
 
     /// <summary>Verifies that InitializeAsync does not warn when probe is disabled.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task InitializeAsync_does_not_warn_when_probe_is_disabled()
     {
@@ -191,9 +196,11 @@ public sealed class AbCipLoggingTests
         /// <summary>Begins a scope (stub implementation).</summary>
         /// <typeparam name="TState">The type of the scope state.</typeparam>
         /// <param name="state">The scope state.</param>
+        /// <returns>A no-op disposable scope.</returns>
         public IDisposable BeginScope<TState>(TState state) where TState : notnull => NullScope.Instance;
         /// <summary>Checks if logging is enabled (always true).</summary>
         /// <param name="logLevel">The log level to check.</param>
+        /// <returns><c>true</c> always — this capturing logger accepts every log level.</returns>
         public bool IsEnabled(LogLevel logLevel) => true;
         /// <summary>Logs an entry and captures it.</summary>
         /// <typeparam name="TState">The type of the log state.</typeparam>