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.FOCAS.Tests/FocasCapabilityTests.cs

@@ -12,6 +12,7 @@ public sealed class FocasCapabilityTests
     // ---- ITagDiscovery ----
 
     /// <summary>Verifies that DiscoverAsync emits pre-declared tags.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task DiscoverAsync_emits_pre_declared_tags()
     {
@@ -41,6 +42,7 @@ public sealed class FocasCapabilityTests
     // ---- ISubscribable ----
 
     /// <summary>Verifies that the initial subscription poll raises an OnDataChange event.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Subscribe_initial_poll_raises_OnDataChange()
     {
@@ -67,6 +69,7 @@ public sealed class FocasCapabilityTests
     }
 
     /// <summary>Verifies that ShutdownAsync cancels active subscriptions.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ShutdownAsync_cancels_active_subscriptions()
     {
@@ -97,6 +100,7 @@ public sealed class FocasCapabilityTests
     // ---- IHostConnectivityProbe ----
 
     /// <summary>Verifies that GetHostStatuses returns one entry per device.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task GetHostStatuses_returns_entry_per_device()
     {
@@ -115,6 +119,7 @@ public sealed class FocasCapabilityTests
     }
 
     /// <summary>Verifies that the probe transitions to Running on successful connection.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Probe_transitions_to_Running_on_success()
     {
@@ -142,6 +147,7 @@ public sealed class FocasCapabilityTests
     }
 
     /// <summary>Verifies that the probe transitions to Stopped on connection failure.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Probe_transitions_to_Stopped_on_failure()
     {
@@ -171,6 +177,7 @@ public sealed class FocasCapabilityTests
     // ---- IPerCallHostResolver ----
 
     /// <summary>Verifies that ResolveHost returns the declared device for a known tag.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ResolveHost_returns_declared_device_for_known_tag()
     {
@@ -195,6 +202,7 @@ public sealed class FocasCapabilityTests
     }
 
     /// <summary>Verifies that ResolveHost falls back to the first device for unknown tags.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ResolveHost_falls_back_to_first_device_for_unknown()
     {
@@ -209,6 +217,7 @@ public sealed class FocasCapabilityTests
     }
 
     /// <summary>Verifies that ResolveHost falls back to the driver instance ID when no devices are configured.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task ResolveHost_falls_back_to_DriverInstanceId_when_no_devices()
     {
@@ -235,40 +244,27 @@ public sealed class FocasCapabilityTests
         /// <summary>Gets the list of recorded variable calls.</summary>
         public List<(string BrowseName, DriverAttributeInfo Info)> Variables { get; } = new();
 
-        /// <summary>Records a folder call.</summary>
-        /// <param name="browseName">The browse name of the folder.</param>
-        /// <param name="displayName">The display name of the folder.</param>
-        /// <returns>This builder for chaining.</returns>
+        /// <inheritdoc />
         public IAddressSpaceBuilder Folder(string browseName, string displayName)
         { Folders.Add((browseName, displayName)); return this; }
 
-        /// <summary>Records a variable call.</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>
-        /// <returns>A variable handle for the recorded variable.</returns>
+        /// <inheritdoc />
         public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo info)
         { Variables.Add((browseName, info)); return new Handle(info.FullName); }
 
-        /// <summary>Records a property call (no-op).</summary>
-        /// <param name="_">The property name (unused).</param>
-        /// <param name="__">The property 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.</summary>
+            /// <inheritdoc />
             public string FullReference => fullRef;
-            /// <summary>Marks as alarm condition.</summary>
-            /// <param name="info">The alarm condition information.</param>
-            /// <returns>An alarm condition sink.</returns>
+            /// <inheritdoc />
             public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NullSink();
         }
         /// <summary>Null alarm condition sink.</summary>
         private sealed class NullSink : IAlarmConditionSink {
-            /// <summary>Handles transition (no-op).</summary>
-            /// <param name="args">The alarm event arguments (unused).</param>
+            /// <inheritdoc />
             public void OnTransition(AlarmEventArgs args) { }
         }
     }