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/AbCipUdtMemberTests.cs

@@ -9,6 +9,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.AbCip.Tests;
 public sealed class AbCipUdtMemberTests
 {
     /// <summary>Verifies that UDT with declared members expands to individual member variables.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task UDT_with_declared_members_fans_out_to_member_variables()
     {
@@ -48,6 +49,7 @@ public sealed class AbCipUdtMemberTests
     }
 
     /// <summary>Verifies that UDT members can be read via synthesised full reference paths.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task UDT_members_resolvable_for_read_via_synthesised_full_reference()
     {
@@ -84,6 +86,7 @@ public sealed class AbCipUdtMemberTests
     }
 
     /// <summary>Verifies that UDT member writes route through synthesised tag paths.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task UDT_member_write_routes_through_synthesised_tagpath()
     {
@@ -110,6 +113,7 @@ public sealed class AbCipUdtMemberTests
     }
 
     /// <summary>Verifies that UDT member read/write operations respect the Writable flag.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task UDT_member_read_write_honours_member_Writable_flag()
     {
@@ -135,6 +139,7 @@ public sealed class AbCipUdtMemberTests
     }
 
     /// <summary>Verifies that structure tags without declared members appear as single variables.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Structure_tag_without_members_is_emitted_as_single_variable()
     {
@@ -156,6 +161,7 @@ public sealed class AbCipUdtMemberTests
     }
 
     /// <summary>Verifies that empty member lists are treated the same as null.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Empty_Members_list_is_treated_like_null()
     {
@@ -174,6 +180,7 @@ public sealed class AbCipUdtMemberTests
     }
 
     /// <summary>Verifies that UDT members and flat tags can coexist in the address space.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task UDT_members_mixed_with_flat_tags_coexist()
     {
@@ -209,39 +216,29 @@ public sealed class AbCipUdtMemberTests
         /// <summary>Gets the collected variables.</summary>
         public List<(string BrowseName, DriverAttributeInfo Info)> Variables { get; } = new();
 
-        /// <summary>Records a folder in the address space.</summary>
-        /// <param name="browseName">The browse name of the folder.</param>
-        /// <param name="displayName">The display name of the folder.</param>
+        /// <inheritdoc />
         public IAddressSpaceBuilder Folder(string browseName, string displayName)
         { Folders.Add((browseName, displayName)); return this; }
 
-        /// <summary>Records a variable in the address space.</summary>
-        /// <param name="browseName">The browse name of the variable.</param>
-        /// <param name="displayName">The display name of the variable.</param>
-        /// <param name="info">The driver attribute information for the variable.</param>
+        /// <inheritdoc />
         public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo info)
         { Variables.Add((browseName, info)); return new Handle(info.FullName); }
 
-        /// <summary>Records a property (stub implementation for testing).</summary>
-        /// <param name="_">The property name (unused in this stub).</param>
-        /// <param name="__">The property data type (unused in this stub).</param>
-        /// <param name="___">The property value (unused in this stub).</param>
+        /// <inheritdoc />
         public void AddProperty(string _, DriverDataType __, object? ___) { }
 
         /// <summary>Variable handle implementation for testing.</summary>
         private sealed class Handle(string fullRef) : IVariableHandle
         {
-            /// <summary>Gets the full reference path.</summary>
+            /// <inheritdoc />
             public string FullReference => fullRef;
-            /// <summary>Marks this handle as an alarm condition.</summary>
-            /// <param name="info">The alarm condition information.</param>
+            /// <inheritdoc />
             public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NullSink();
         }
         /// <summary>Null alarm condition sink for testing.</summary>
         private sealed class NullSink : IAlarmConditionSink
         {
-            /// <summary>Handles alarm transitions (stub).</summary>
-            /// <param name="args">The alarm event arguments.</param>
+            /// <inheritdoc />
             public void OnTransition(AlarmEventArgs args) { }
         }
     }