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.TwinCAT.Tests/TwinCATSymbolBrowserTests.cs

@@ -9,6 +9,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests;
 public sealed class TwinCATSymbolBrowserTests
 {
     /// <summary>Verifies that discovery without EnableControllerBrowse only emits predeclared tags.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Discovery_without_EnableControllerBrowse_emits_only_predeclared()
     {
@@ -38,6 +39,7 @@ public sealed class TwinCATSymbolBrowserTests
     }
 
     /// <summary>Verifies that discovery with browse enabled adds controller symbols under Discovered folder.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Discovery_with_browse_enabled_adds_controller_symbols_under_Discovered_folder()
     {
@@ -68,6 +70,7 @@ public sealed class TwinCATSymbolBrowserTests
     }
 
     /// <summary>Verifies that browse filters out system symbols correctly.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Browse_filters_system_symbols()
     {
@@ -99,6 +102,7 @@ public sealed class TwinCATSymbolBrowserTests
     }
 
     /// <summary>Verifies that browse skips symbols with null datatype.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Browse_skips_symbols_with_null_datatype()
     {
@@ -127,6 +131,7 @@ public sealed class TwinCATSymbolBrowserTests
     }
 
     /// <summary>Verifies that read-only symbols surface as ViewOnly.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ReadOnly_symbol_surfaces_ViewOnly()
     {
@@ -154,6 +159,7 @@ public sealed class TwinCATSymbolBrowserTests
     }
 
     /// <summary>Verifies that browse failure is non-fatal and predeclared tags still emit.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Browse_failure_is_non_fatal_predeclared_still_emits()
     {
@@ -252,9 +258,7 @@ public sealed class TwinCATSymbolBrowserTests
             public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NullSink();
         }
 
-        /// <summary>
-        /// A null implementation of IAlarmConditionSink for test purposes.
-        /// </summary>
+        /// <summary>A null implementation of IAlarmConditionSink for test purposes.</summary>
         private sealed class NullSink : IAlarmConditionSink
         {
             /// <summary>