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/Health/PerPlatformProbeWatcherTests.cs

@@ -27,10 +27,7 @@ public sealed class PerPlatformProbeWatcherTests
         /// <summary>Gets a mapping of tag addresses to their assigned item handles.</summary>
         public Dictionary<string, int> HandleByAddress { get; } = new(StringComparer.OrdinalIgnoreCase);
 
-        /// <summary>Simulates a bulk subscribe operation by generating handles for each reference.</summary>
-        /// <param name="fullReferences">The list of tag addresses to subscribe to.</param>
-        /// <param name="bufferedUpdateIntervalMs">The buffered update interval in milliseconds.</param>
-        /// <param name="cancellationToken">The cancellation token for the operation.</param>
+        /// <inheritdoc />
         public Task<IReadOnlyList<SubscribeResult>> SubscribeBulkAsync(
             IReadOnlyList<string> fullReferences, int bufferedUpdateIntervalMs, CancellationToken cancellationToken)
         {
@@ -51,17 +48,14 @@ public sealed class PerPlatformProbeWatcherTests
             return Task.FromResult<IReadOnlyList<SubscribeResult>>(results);
         }
 
-        /// <summary>Simulates a bulk unsubscribe operation by recording the handles.</summary>
-        /// <param name="itemHandles">The list of item handles to unsubscribe.</param>
-        /// <param name="cancellationToken">The cancellation token for the operation.</param>
+        /// <inheritdoc />
         public Task UnsubscribeBulkAsync(IReadOnlyList<int> itemHandles, CancellationToken cancellationToken)
         {
             Unsubscribes.Add([.. itemHandles]);
             return Task.CompletedTask;
         }
 
-        /// <summary>Returns an empty event stream for testing.</summary>
-        /// <param name="cancellationToken">The cancellation token for the operation.</param>
+        /// <inheritdoc />
         public IAsyncEnumerable<MxEvent> StreamEventsAsync(CancellationToken cancellationToken)
             => Empty();
 
@@ -73,6 +67,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that syncing platforms subscribes to the ScanState address for each platform.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SyncPlatformsAsync_SubscribesScanStateAddressForEachPlatform()
     {
@@ -88,6 +83,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that the default buffered interval is zero, matching gateway cadence.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SyncPlatformsAsync_DefaultBufferedIntervalIsZero_GwCadence()
     {
@@ -100,6 +96,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that a configured buffered interval is forwarded to the gateway.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SyncPlatformsAsync_ConfiguredBufferedInterval_IsForwardedToGw()
     {
@@ -125,6 +122,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that syncing the same platform set twice does not resubscribe.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SyncPlatformsAsync_SameSetTwice_DoesNotResubscribe()
     {
@@ -139,6 +137,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that removed platforms are unsubscribed and dropped from the aggregator.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SyncPlatformsAsync_RemovedPlatforms_AreUnsubscribed_AndDroppedFromAggregator()
     {
@@ -183,6 +182,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that a running probe value is routed to the aggregator.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task OnProbeValueChanged_Running_RoutesToAggregator()
     {
@@ -198,6 +198,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that a probe value with bad quality routes as unknown state.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task OnProbeValueChanged_BadQuality_RoutesUnknown()
     {
@@ -212,6 +213,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that foreign probe references are silently dropped.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task OnProbeValueChanged_ForeignReference_IsSilentlyDropped()
     {
@@ -231,6 +233,7 @@ public sealed class PerPlatformProbeWatcherTests
     }
 
     /// <summary>Verifies that dispose unsubscribes all tracked platforms.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Dispose_UnsubscribesAllTrackedPlatforms()
     {