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.AbLegacy.Tests/AbLegacyCapabilityTests.cs

@@ -12,6 +12,7 @@ public sealed class AbLegacyCapabilityTests
     // ---- ITagDiscovery ----
 
     /// <summary>Verifies that DiscoverAsync emits pre-declared tags under the device folder.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task DiscoverAsync_emits_pre_declared_tags_under_device_folder()
     {
@@ -40,6 +41,7 @@ public sealed class AbLegacyCapabilityTests
     // ---- ISubscribable ----
 
     /// <summary>Verifies that Subscribe initial poll raises OnDataChange.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Subscribe_initial_poll_raises_OnDataChange()
     {
@@ -66,6 +68,7 @@ public sealed class AbLegacyCapabilityTests
     }
 
     /// <summary>Verifies that Unsubscribe halts polling.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Unsubscribe_halts_polling()
     {
@@ -96,6 +99,7 @@ public sealed class AbLegacyCapabilityTests
     // ---- IHostConnectivityProbe ----
 
     /// <summary>Verifies that GetHostStatuses returns one status per device.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task GetHostStatuses_returns_one_per_device()
     {
@@ -114,6 +118,7 @@ public sealed class AbLegacyCapabilityTests
     }
 
     /// <summary>Verifies that Probe transitions to Running on successful read.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Probe_transitions_to_Running_on_successful_read()
     {
@@ -138,6 +143,7 @@ public sealed class AbLegacyCapabilityTests
     }
 
     /// <summary>Verifies that Probe transitions to Stopped on read failure.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Probe_transitions_to_Stopped_on_read_failure()
     {
@@ -162,6 +168,7 @@ public sealed class AbLegacyCapabilityTests
     }
 
     /// <summary>Verifies that Probe is disabled when ProbeAddress is null.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task Probe_disabled_when_ProbeAddress_is_null()
     {
@@ -180,6 +187,7 @@ public sealed class AbLegacyCapabilityTests
     // ---- IPerCallHostResolver ----
 
     /// <summary>Verifies that ResolveHost returns declared device for known tag.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ResolveHost_returns_declared_device_for_known_tag()
     {
@@ -204,6 +212,7 @@ public sealed class AbLegacyCapabilityTests
     }
 
     /// <summary>Verifies that ResolveHost falls back to first device for unknown tags.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ResolveHost_falls_back_to_first_device_for_unknown()
     {
@@ -218,6 +227,7 @@ public sealed class AbLegacyCapabilityTests
     }
 
     /// <summary>Verifies that ResolveHost falls back to DriverInstanceId when no devices exist.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ResolveHost_falls_back_to_DriverInstanceId_when_no_devices()
     {
@@ -243,31 +253,22 @@ public sealed class AbLegacyCapabilityTests
         /// <summary>Gets list of variables created during discovery.</summary>
         public List<(string BrowseName, DriverAttributeInfo Info)> Variables { get; } = new();
 
-        /// <summary>Records folder creation.</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 variable creation.</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.</param>
+        /// <inheritdoc />
         public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo info)
         { Variables.Add((browseName, info)); return new Handle(info.FullName); }
 
-        /// <summary>Records property addition (stub implementation).</summary>
-        /// <param name="_">The property name (unused).</param>
-        /// <param name="__">The data type (unused).</param>
-        /// <param name="___">The property value (unused).</param>
+        /// <inheritdoc />
         public void AddProperty(string _, DriverDataType __, object? ___) { }
 
         private sealed class Handle(string fullRef) : IVariableHandle
         {
-            /// <summary>Gets the full reference of the variable.</summary>
+            /// <inheritdoc />
             public string FullReference => fullRef;
-            /// <summary>Marks the variable as an alarm condition.</summary>
-            /// <param name="info">The alarm condition information.</param>
+            /// <inheritdoc />
             public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NullSink();
         }
         /// <summary>Null sink for alarm condition transitions.</summary>