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.Historian.Wonderware.Tests/Ipc/PipeRoundTripTests.cs

@@ -93,11 +93,10 @@ public sealed class PipeRoundTripTests
         public Task<List<BackendHistorianEventDto>> ReadEventsAsync(string? sourceName, DateTime startTime, DateTime endTime, int maxEvents, CancellationToken ct = default)
             => Task.FromResult(Events);
 
-        /// <summary>Gets a health snapshot of the fake historian.</summary>
-        /// <returns>A health snapshot.</returns>
+        /// <inheritdoc />
         public HistorianHealthSnapshot GetHealthSnapshot() => new();
 
-        /// <summary>Disposes the fake historian.</summary>
+        /// <inheritdoc />
         public void Dispose() { }
     }
 
@@ -153,6 +152,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that raw historian samples round-trip correctly through the frame handler.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ReadRaw_RoundTripsSamples()
     {
@@ -183,6 +183,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that read failures are properly surfaced as error replies.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ReadRaw_FailureSurfacesAsErrorReply()
     {
@@ -199,6 +200,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that processed (aggregate) historian samples round-trip correctly through the frame handler.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ReadProcessed_RoundTripsBuckets()
     {
@@ -219,6 +221,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that at-time historian samples round-trip correctly through the frame handler.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ReadAtTime_RoundTripsSamples()
     {
@@ -240,6 +243,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that historian events round-trip correctly through the frame handler.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task ReadEvents_RoundTripsEvents()
     {
@@ -270,6 +274,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that alarm events are routed to the writer and per-event status is returned.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task WriteAlarmEvents_RoutesToWriter_AndReturnsPerEventStatus()
     {
@@ -303,6 +308,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that writing alarm events fails cleanly when no writer is configured.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task WriteAlarmEvents_FailsCleanly_WhenNoWriterConfigured()
     {
@@ -324,6 +330,7 @@ public sealed class PipeRoundTripTests
     }
 
     /// <summary>Verifies that frame reader and writer preserve message kind and body through a round trip.</summary>
+    /// <returns>A task that represents the asynchronous test operation.</returns>
     [Fact]
     public async Task FrameReader_FrameWriter_RoundTripPreservesKindAndBody()
     {

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Tests/Ipc/PipeServerSidRejectTests.cs

@@ -27,6 +27,7 @@ public sealed class PipeServerSidRejectTests
     private static readonly ILogger Quiet = Logger.None;
 
     /// <summary>Verifies that a caller SID mismatch sends HelloAck with reject reason before disconnect.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Caller_SID_mismatch_sends_HelloAck_with_reject_reason_before_disconnect()
     {