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.AbLegacy.IntegrationTests/AbLegacyReadSmokeTests.cs

@@ -22,6 +22,7 @@ public sealed class AbLegacyReadSmokeTests(AbLegacyServerFixture sim)
     // filters to that profile alone so the suite matches the running container. Unset
     // (the default for real-hardware runs) parameterises across every family the driver
     // supports.
+    /// <summary>Gets the available server profiles based on compose configuration.</summary>
     public static IEnumerable<object[]> Profiles
     {
         get
@@ -34,6 +35,8 @@ public sealed class AbLegacyReadSmokeTests(AbLegacyServerFixture sim)
         }
     }
 
+    /// <summary>Verifies that the driver reads seeded N file from the AB server via PCCC.</summary>
+    /// <param name="profile">The AB Legacy server profile describing the fixture endpoint.</param>
     [AbLegacyTheory]
     [MemberData(nameof(Profiles))]
     public async Task Driver_reads_seeded_N_file_from_ab_server_PCCC(AbLegacyServerProfile profile)
@@ -69,6 +72,7 @@ public sealed class AbLegacyReadSmokeTests(AbLegacyServerFixture sim)
         drv.GetHealth().State.ShouldBe(DriverState.Healthy);
     }
 
+    /// <summary>Verifies that SLC500 write-then-read round trip succeeds on N7 scratch register.</summary>
     [AbLegacyFact]
     public async Task Slc500_write_then_read_round_trip_on_N7_scratch_register()
     {

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/AbLegacyServerFixture.cs

@@ -53,15 +53,20 @@ public sealed class AbLegacyServerFixture : IAsyncLifetime
     // 10.100.0.35 = the shared Docker host (see CLAUDE.md "Docker Workflow"). Migrated
     // off this VM's 127.0.0.1 on 2026-04-28 alongside the rest of the Docker-host move.
     // Override via AB_LEGACY_ENDPOINT to point at a real PLC or a locally-running container.
+    /// <summary>Gets the server host address.</summary>
     public string Host { get; } = "10.100.0.35";
+
+    /// <summary>Gets the server TCP port.</summary>
     public int Port { get; } = DefaultPort;
 
     /// <summary>CIP routing path portion of the device URI (after the <c>/</c> separator).
     /// May be empty when targeting real hardware; non-empty against ab_server.</summary>
     public string CipPath { get; } = DefaultCipPath;
 
+    /// <summary>Gets the skip reason if the server is unavailable, or null if available.</summary>
     public string? SkipReason { get; }
 
+    /// <summary>Initializes the AB Legacy server fixture by reading environment overrides.</summary>
     public AbLegacyServerFixture()
     {
         if (Environment.GetEnvironmentVariable(EndpointEnvVar) is { Length: > 0 } raw)
@@ -79,7 +84,10 @@ public sealed class AbLegacyServerFixture : IAsyncLifetime
         SkipReason = ResolveSkipReason(Host, Port);
     }
 
+    /// <summary>Initializes the fixture asynchronously.</summary>
     public ValueTask InitializeAsync() => ValueTask.CompletedTask;
+
+    /// <summary>Disposes the fixture asynchronously.</summary>
     public ValueTask DisposeAsync() => ValueTask.CompletedTask;
 
     /// <summary>
@@ -155,9 +163,12 @@ public static class KnownProfiles
         ComposeProfile: "plc5",
         Notes: "PLC-5 family. ab_server PLC/5 mode covers N/F/B; per-family quirks on ST / timer file layouts unit-tested only.");
 
+    /// <summary>Gets all known profiles.</summary>
     public static IReadOnlyList<AbLegacyServerProfile> All { get; } =
         [Slc500, MicroLogix, Plc5];
 
+    /// <summary>Gets the profile for the specified PLC family.</summary>
+    /// <param name="family">The PLC family.</param>
     public static AbLegacyServerProfile ForFamily(AbLegacyPlcFamily family) =>
         All.FirstOrDefault(p => p.Family == family)
         ?? throw new ArgumentOutOfRangeException(nameof(family), family, "No integration profile for this family.");
@@ -175,6 +186,7 @@ public sealed class AbLegacyServerCollection : Xunit.ICollectionFixture<AbLegacy
 /// </summary>
 public sealed class AbLegacyFactAttribute : FactAttribute
 {
+    /// <summary>Initializes the attribute, skipping the test if the server is unavailable.</summary>
     public AbLegacyFactAttribute()
     {
         if (!AbLegacyServerFixture.IsServerAvailable())
@@ -189,6 +201,7 @@ public sealed class AbLegacyFactAttribute : FactAttribute
 /// </summary>
 public sealed class AbLegacyTheoryAttribute : TheoryAttribute
 {
+    /// <summary>Initializes the attribute, skipping the test if the server is unavailable.</summary>
     public AbLegacyTheoryAttribute()
     {
         if (!AbLegacyServerFixture.IsServerAvailable())