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.Galaxy.Tests/Runtime/GalaxyDriverSubscribeTests.cs

@@ -40,11 +40,7 @@ public sealed class GalaxyDriverSubscribeTests
         /// <summary>Gets or sets a function to decide whether to accept a subscription.</summary>
         public Func<string, bool> Decide { get; set; } = _ => true;
 
-        /// <summary>Subscribes to bulk updates for the specified tag references.</summary>
-        /// <param name="fullReferences">The tag references to subscribe to.</param>
-        /// <param name="bufferedUpdateIntervalMs">The buffered update interval in milliseconds.</param>
-        /// <param name="cancellationToken">Cancellation token for the operation.</param>
-        /// <returns>A list of subscription results.</returns>
+        /// <inheritdoc />
         public Task<IReadOnlyList<SubscribeResult>> SubscribeBulkAsync(
             IReadOnlyList<string> fullReferences, int bufferedUpdateIntervalMs, CancellationToken cancellationToken)
         {
@@ -77,19 +73,14 @@ public sealed class GalaxyDriverSubscribeTests
             return Task.FromResult<IReadOnlyList<SubscribeResult>>(results);
         }
 
-        /// <summary>Unsubscribes from bulk updates for the specified item handles.</summary>
-        /// <param name="itemHandles">The handles to unsubscribe.</param>
-        /// <param name="cancellationToken">Cancellation token for the operation.</param>
-        /// <returns>A completed task.</returns>
+        /// <inheritdoc />
         public Task UnsubscribeBulkAsync(IReadOnlyList<int> itemHandles, CancellationToken cancellationToken)
         {
             UnsubscribedHandles.AddRange(itemHandles);
             return Task.CompletedTask;
         }
 
-        /// <summary>Streams events asynchronously.</summary>
-        /// <param name="cancellationToken">Cancellation token for the operation.</param>
-        /// <returns>An async enumerable of MX events.</returns>
+        /// <inheritdoc />
         public IAsyncEnumerable<MxEvent> StreamEventsAsync(CancellationToken cancellationToken)
             => _events.Reader.ReadAllAsync(cancellationToken);
 
@@ -113,6 +104,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies subscription allocates a handle and dispatches value changes.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_AllocatesHandle_AndDispatchesValueChange()
     {
@@ -136,6 +128,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies two subscriptions for the same tag each receive updates.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_TwoSubscriptions_SameTag_FanOutOnePerSubscription()
     {
@@ -180,6 +173,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies failed subscriptions do not dispatch events.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_FailedTag_DoesNotDispatchEvents()
     {
@@ -201,6 +195,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies unsubscribe removes registration and calls gateway unsubscribe.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task UnsubscribeAsync_RemovesRegistration_AndCallsGwUnsubscribe()
     {
@@ -224,6 +219,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies unsubscribing with an unknown handle is handled.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task UnsubscribeAsync_UnknownHandle_NoOp()
     {
@@ -239,6 +235,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies subscription without a subscriber throws.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_NoSubscriber_Throws()
     {
@@ -249,6 +246,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies subscription falls back to configured interval when zero is passed.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_FallsBackToConfiguredInterval_WhenCallerPassesZero()
     {
@@ -269,6 +267,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies subscription respects caller's interval when non-zero.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_RespectsCallerInterval_WhenNonZero()
     {
@@ -289,6 +288,7 @@ public sealed class GalaxyDriverSubscribeTests
     }
 
     /// <summary>Verifies subscription with empty tag list returns handle without calling gateway.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task SubscribeAsync_EmptyTagList_ReturnsHandleWithoutCallingGw()
     {
@@ -304,7 +304,7 @@ public sealed class GalaxyDriverSubscribeTests
     /// <summary>A subscription handle from a foreign source.</summary>
     private sealed class ForeignHandle : ISubscriptionHandle
     {
-        /// <summary>Gets the diagnostic identifier for this handle.</summary>
+        /// <inheritdoc />
         public string DiagnosticId => "foreign-x";
     }