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/Core/ZB.MOM.WW.OtOpcUa.Core.Tests/Stability/ScheduledRecycleSchedulerTests.cs

@@ -36,6 +36,7 @@ public sealed class ScheduledRecycleSchedulerTests
     }
 
     /// <summary>Verifies Tick before the next recycle time is a no-op.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Tick_BeforeNextRecycle_NoOp()
     {
@@ -49,6 +50,7 @@ public sealed class ScheduledRecycleSchedulerTests
     }
 
     /// <summary>Verifies Tick at or after the next recycle time fires once and advances.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Tick_AtOrAfterNextRecycle_FiresOnce_AndAdvances()
     {
@@ -63,6 +65,7 @@ public sealed class ScheduledRecycleSchedulerTests
     }
 
     /// <summary>Verifies RequestRecycleNow fires immediately without advancing the schedule.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task RequestRecycleNow_Fires_Immediately_WithoutAdvancingSchedule()
     {
@@ -78,6 +81,7 @@ public sealed class ScheduledRecycleSchedulerTests
     }
 
     /// <summary>Verifies multiple ticks across the recycle interval each advance by one interval.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task MultipleFires_AcrossTicks_AdvanceOneIntervalEach()
     {
@@ -95,7 +99,7 @@ public sealed class ScheduledRecycleSchedulerTests
     /// <summary>Fake driver supervisor for testing.</summary>
     private sealed class FakeSupervisor : IDriverSupervisor
     {
-        /// <summary>Gets the driver instance ID.</summary>
+        /// <inheritdoc />
         public string DriverInstanceId => "tier-c-fake";
 
         /// <summary>Gets the number of times RecycleAsync was called.</summary>
@@ -104,10 +108,7 @@ public sealed class ScheduledRecycleSchedulerTests
         /// <summary>Gets the reason from the most recent recycle call.</summary>
         public string? LastReason { get; private set; }
 
-        /// <summary>Simulates a driver recycle operation.</summary>
-        /// <param name="reason">The reason for the recycle.</param>
-        /// <param name="cancellationToken">Cancellation token.</param>
-        /// <returns>A completed task.</returns>
+        /// <inheritdoc />
         public Task RecycleAsync(string reason, CancellationToken cancellationToken)
         {
             RecycleCount++;