docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests/TwinCAT3SmokeTests.cs

@@ -33,6 +33,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests;
 [Trait("Simulator", "TwinCAT-XAR")]
 public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
 {
+    /// <summary>Verifies that the driver reads a seeded DINT value through real ADS.</summary>
     [TwinCATFact]
     public async Task Driver_reads_seeded_DINT_through_real_ADS()
     {
@@ -54,6 +55,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         Convert.ToInt32(snapshots[0].Value).ShouldBeGreaterThanOrEqualTo(0);
     }
 
+    /// <summary>Verifies a write-then-read round trip on a scratch REAL variable.</summary>
     [TwinCATFact]
     public async Task Driver_write_then_read_round_trip_on_scratch_REAL()
     {
@@ -77,6 +79,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         Convert.ToSingle(readResults[0].Value).ShouldBe(probe, tolerance: 0.001f);
     }
 
+    /// <summary>Verifies that the driver receives native ADS notifications on counter value changes.</summary>
     [TwinCATFact]
     public async Task Driver_subscribe_receives_native_ADS_notifications_on_counter_changes()
     {
@@ -113,6 +116,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         await drv.UnsubscribeAsync(handle, TestContext.Current.CancellationToken);
     }
 
+    /// <summary>Verifies that the driver browses the committed symbol hierarchy via real ADS.</summary>
     [TwinCATFact]
     public async Task Driver_browses_committed_symbol_hierarchy_via_real_ADS()
     {
@@ -153,6 +157,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         symbols.ShouldContain(s => s.InstancePath == "GVL_Enums.currentAxisState");
     }
 
+    /// <summary>Verifies that the driver round-trips array element write and read operations.</summary>
     [TwinCATFact]
     public async Task Driver_round_trips_array_element_write_and_read()
     {
@@ -179,6 +184,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         Convert.ToSingle(readResults[0].Value).ShouldBe(probe, tolerance: 0.001f);
     }
 
+    /// <summary>Verifies that the driver auto-reconnects after the underlying ADS client is disposed.</summary>
     [TwinCATFact]
     public async Task Driver_auto_reconnects_after_underlying_client_is_disposed()
     {
@@ -205,6 +211,10 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         second[0].StatusCode.ShouldBe(0u, "driver must transparently reconnect on next read");
     }
 
+    /// <summary>Verifies that the driver reads every primitive type with correct mapping.</summary>
+    /// <param name="symbolPath">The TwinCAT symbol path to read.</param>
+    /// <param name="type">The TwinCAT data type of the symbol.</param>
+    /// <param name="expectedValueInvariant">The expected value in culture-invariant format, or null to skip value assertion.</param>
     [TwinCATTheory]
     // vBool's expected value is null — the initial TRUE seed doesn't reliably survive cold
     // restarts on this deployment, and the point of this theory is round-tripping the type
@@ -285,6 +295,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         }
     }
 
+    /// <summary>Verifies that the driver reads bit-indexed BOOL values from word symbols.</summary>
     [TwinCATFact]
     public async Task Driver_reads_bit_indexed_BOOL_from_word()
     {
@@ -323,6 +334,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         result[1].Value.ShouldBe(false,  "bit 4 of 0xBEEF is clear");
     }
 
+    /// <summary>Verifies that the driver reads deeply nested UDT member paths.</summary>
     [TwinCATFact]
     public async Task Driver_reads_deeply_nested_UDT_path()
     {
@@ -360,6 +372,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         result[1].Value.ShouldBeOfType<bool>();
     }
 
+    /// <summary>Verifies that the driver reports errors for unknown tags, nonexistent symbols, and read-only writes.</summary>
     [TwinCATFact]
     public async Task Driver_reports_errors_for_unknown_tag_and_nonexistent_symbol_and_readonly_write()
     {
@@ -410,6 +423,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         roWrite[0].StatusCode.ShouldBe(TwinCATStatusMapper.BadNotWritable);
     }
 
+    /// <summary>Verifies that the driver routes reads per device and isolates unreachable peers.</summary>
     [TwinCATFact]
     public async Task Driver_routes_reads_per_device_and_isolates_unreachable_peers()
     {
@@ -461,6 +475,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         drv.ResolveHost("GhostCounter").ShouldBe(ghostHost);
     }
 
+    /// <summary>Verifies that the probe loop raises a host status transition to Running when the target is reachable.</summary>
     [TwinCATFact]
     public async Task Probe_loop_raises_host_status_transition_to_Running_on_reachable_target()
     {
@@ -504,6 +519,7 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
         statuses[0].State.ShouldBe(HostState.Running);
     }
 
+    /// <summary>Verifies that DiscoverAsync renders declared tags and controller browse symbols to the address space builder.</summary>
     [TwinCATFact]
     public async Task DiscoverAsync_renders_declared_tags_and_controller_browse_hits_address_space_builder()
     {
@@ -585,33 +601,55 @@ public sealed class TwinCAT3SmokeTests(TwinCATXarFixture sim)
 /// </summary>
 internal sealed class RecordingAddressSpaceBuilder : IAddressSpaceBuilder
 {
+    /// <summary>Gets the list of recorded folder calls.</summary>
     public List<(string BrowseName, string DisplayName)> Folders { get; } = [];
+    /// <summary>Gets the list of recorded variable calls.</summary>
     public List<(string BrowseName, DriverAttributeInfo Info)> Variables { get; } = [];
 
+    /// <summary>Gets the browse names of all recorded folders.</summary>
     public IEnumerable<string> FolderBrowseNames => Folders.Select(f => f.BrowseName);
 
+    /// <summary>Records a folder call and returns this builder for chaining.</summary>
+    /// <param name="browseName">The browse name of the folder.</param>
+    /// <param name="displayName">The display name of the folder.</param>
+    /// <returns>This builder instance for method chaining.</returns>
     public IAddressSpaceBuilder Folder(string browseName, string displayName)
     {
         Folders.Add((browseName, displayName));
         return this;
     }
 
+    /// <summary>Records a variable call and returns a handle for it.</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>
     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 in this test double).</summary>
+    /// <param name="name">The property name.</param>
+    /// <param name="type">The property data type.</param>
+    /// <param name="value">The property value.</param>
     public void AddProperty(string name, DriverDataType type, object? value) { }
 
     private sealed class Handle(string fullRef) : IVariableHandle
     {
+        /// <summary>Gets the full reference of the variable.</summary>
         public string FullReference => fullRef;
+        /// <summary>Marks the variable as an alarm condition with the specified information.</summary>
+        /// <param name="info">Alarm condition information.</param>
+        /// <returns>An alarm condition sink for handling transitions.</returns>
         public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info) => new NullSink();
     }
 
     private sealed class NullSink : IAlarmConditionSink
     {
+        /// <summary>Handles an alarm condition transition (no-op in this test double).</summary>
+        /// <param name="args">The alarm event arguments.</param>
         public void OnTransition(AlarmEventArgs args) { }
     }
 }

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.IntegrationTests/TwinCATXarFixture.cs

@@ -55,11 +55,16 @@ public sealed class TwinCATXarFixture : IAsyncLifetime
     /// <summary>TC3 PLC runtime 1. Override via <see cref="PortEnvVar"/>.</summary>
     public const int DefaultAmsPort = 851;
 
+    /// <summary>Gets the target host address.</summary>
     public string TargetHost { get; }
+    /// <summary>Gets the target AMS NetId.</summary>
     public string? TargetNetId { get; }
+    /// <summary>Gets the AMS target port.</summary>
     public int AmsPort { get; }
+    /// <summary>Gets the reason to skip tests if the fixture is unreachable.</summary>
     public string? SkipReason { get; }
 
+    /// <summary>Initializes a new instance of the TwinCATXarFixture class.</summary>
     public TwinCATXarFixture()
     {
         TargetHost  = Environment.GetEnvironmentVariable(HostEnvVar)  ?? "localhost";
@@ -82,7 +87,9 @@ public sealed class TwinCATXarFixture : IAsyncLifetime
         }
     }
 
+    /// <inheritdoc />
     public ValueTask InitializeAsync() => ValueTask.CompletedTask;
+    /// <inheritdoc />
     public ValueTask DisposeAsync() => ValueTask.CompletedTask;
 
     /// <summary><c>true</c> when the XAR runtime is reachable + the AmsNetId is set.
@@ -116,6 +123,7 @@ public sealed class TwinCATXarCollection : Xunit.ICollectionFixture<TwinCATXarFi
 /// <summary><c>[Fact]</c>-equivalent gated on <see cref="TwinCATXarFixture.IsRuntimeAvailable"/>.</summary>
 public sealed class TwinCATFactAttribute : FactAttribute
 {
+    /// <summary>Initializes a new instance of the TwinCATFactAttribute class.</summary>
     public TwinCATFactAttribute()
     {
         if (!TwinCATXarFixture.IsRuntimeAvailable())
@@ -127,6 +135,7 @@ public sealed class TwinCATFactAttribute : FactAttribute
 /// <summary><c>[Theory]</c>-equivalent with the same gate as <see cref="TwinCATFactAttribute"/>.</summary>
 public sealed class TwinCATTheoryAttribute : TheoryAttribute
 {
+    /// <summary>Initializes a new instance of the TwinCATTheoryAttribute class.</summary>
     public TwinCATTheoryAttribute()
     {
         if (!TwinCATXarFixture.IsRuntimeAvailable())