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/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/AdminOperationsActorTests.cs

@@ -13,6 +13,7 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;
 
 public sealed class AdminOperationsActorTests : ControlPlaneActorTestBase
 {
+    /// <summary>Verifies that starting a deployment inserts a row and dispatches to the coordinator.</summary>
     [Fact]
     public void StartDeployment_inserts_deployment_and_dispatches_to_coordinator()
     {
@@ -41,6 +42,7 @@ public sealed class AdminOperationsActorTests : ControlPlaneActorTestBase
         db.ConfigEdits.Single().EntityType.ShouldBe("Deployment");
     }
 
+    /// <summary>Verifies that starting a deployment is refused when another is in flight.</summary>
     [Fact]
     public void StartDeployment_refuses_when_another_is_in_flight()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/AuditWriterActorTests.cs

@@ -21,6 +21,7 @@ public sealed class AuditWriterActorTests : ControlPlaneActorTestBase
             SourceNode: NodeId.Parse("node-a"),
             CorrelationId: CorrelationId.NewId());
 
+    /// <summary>Verifies that buffered events flush when count threshold is reached.</summary>
     [Fact]
     public void Buffered_events_flush_on_count_threshold()
     {
@@ -39,6 +40,7 @@ public sealed class AuditWriterActorTests : ControlPlaneActorTestBase
         }, duration: TimeSpan.FromSeconds(2));
     }
 
+    /// <summary>Verifies that duplicate event IDs within a batch are deduplicated in the buffer.</summary>
     [Fact]
     public void Duplicate_eventIds_within_a_batch_dedup_in_buffer()
     {
@@ -59,6 +61,7 @@ public sealed class AuditWriterActorTests : ControlPlaneActorTestBase
         db.ConfigAuditLogs.Count().ShouldBe(100, "in-buffer dedup should collapse duplicate EventIds");
     }
 
+    /// <summary>Verifies that PostStop flushes the pending buffer.</summary>
     [Fact]
     public void PostStop_flushes_pending_buffer()
     {
@@ -77,6 +80,7 @@ public sealed class AuditWriterActorTests : ControlPlaneActorTestBase
         db.ConfigAuditLogs.Count().ShouldBe(10);
     }
 
+    /// <summary>Verifies that EventId and CorrelationId are persisted to dedicated columns.</summary>
     [Fact]
     public void EventId_and_CorrelationId_are_persisted_to_dedicated_columns()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/ConfigComposerTests.cs

@@ -9,6 +9,7 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;
 
 public sealed class ConfigComposerTests : ControlPlaneActorTestBase
 {
+    /// <summary>Verifies that an empty database produces a stable, reproducible hash.</summary>
     [Fact]
     public async Task Empty_database_produces_stable_hash()
     {
@@ -24,6 +25,7 @@ public sealed class ConfigComposerTests : ControlPlaneActorTestBase
         a1.Blob.ShouldBe(a2.Blob);
     }
 
+    /// <summary>Verifies that insertion order does not affect the configuration hash.</summary>
     [Fact]
     public async Task Same_rows_in_different_insert_orders_produce_same_hash()
     {
@@ -51,6 +53,7 @@ public sealed class ConfigComposerTests : ControlPlaneActorTestBase
         hashAB.ShouldBe(hashBA);
     }
 
+    /// <summary>Verifies that different database configurations produce different hashes.</summary>
     [Fact]
     public async Task Different_data_produces_different_hash()
     {
@@ -72,6 +75,7 @@ public sealed class ConfigComposerTests : ControlPlaneActorTestBase
         hashAB.ShouldNotBe(hashA);
     }
 
+    /// <summary>Verifies that the revision hash is a 64-character lowercase hexadecimal string.</summary>
     [Fact]
     public async Task Hash_is_64_lowercase_hex_chars()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/ConfigPublishCoordinatorTests.cs

@@ -13,6 +13,7 @@ public sealed class ConfigPublishCoordinatorTests : ControlPlaneActorTestBase
 {
     private static readonly RevisionHash TestRevision = RevisionHash.Parse(new string('a', 64));
 
+    /// <summary>Verifies that deployment seals immediately when no driver-role members are in the cluster.</summary>
     [Fact]
     public void EmptyCluster_dispatch_seals_immediately()
     {
@@ -32,6 +33,7 @@ public sealed class ConfigPublishCoordinatorTests : ControlPlaneActorTestBase
         }, duration: TimeSpan.FromSeconds(3));
     }
 
+    /// <summary>Verifies that stale apply acknowledgments arriving after seal are ignored.</summary>
     [Fact]
     public void Stale_ApplyAck_after_seal_is_ignored()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/ConfigPublishCoordinatorTimeoutTests.cs

@@ -15,6 +15,7 @@ public sealed class ConfigPublishCoordinatorTimeoutTests : ControlPlaneActorTest
 {
     private static readonly RevisionHash TestRevision = RevisionHash.Parse(new string('b', 64));
 
+    /// <summary>Verifies that DeadlineElapsed marks the current deployment as timed out.</summary>
     [Fact]
     public void DeadlineElapsed_for_current_deployment_marks_TimedOut()
     {
@@ -48,6 +49,7 @@ public sealed class ConfigPublishCoordinatorTimeoutTests : ControlPlaneActorTest
         }, duration: TimeSpan.FromSeconds(3));
     }
 
+    /// <summary>Verifies that stale DeadlineElapsed for other deployments is ignored.</summary>
     [Fact]
     public void Stale_DeadlineElapsed_for_other_deployment_is_ignored()
     {
@@ -66,6 +68,7 @@ public sealed class ConfigPublishCoordinatorTimeoutTests : ControlPlaneActorTest
         status.ShouldNotBe(DeploymentStatus.TimedOut);
     }
 
+    /// <summary>Verifies that PreStart recovers in-flight deployment state.</summary>
     [Fact]
     public void PreStart_recovers_inflight_deployment_state()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/FleetStatusBroadcasterTests.cs

@@ -10,6 +10,7 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;
 
 public sealed class FleetStatusBroadcasterTests : ControlPlaneActorTestBase
 {
+    /// <summary>Verifies that the self member's join appears in the initial fleet status snapshot.</summary>
     [Fact]
     public void Self_member_up_lands_in_snapshot()
     {
@@ -22,6 +23,7 @@ public sealed class FleetStatusBroadcasterTests : ControlPlaneActorTestBase
         snapshot.Nodes.Any(n => n.Health == FleetNodeHealth.Healthy).ShouldBeTrue();
     }
 
+    /// <summary>Verifies that heartbeat messages update the node revision in the next broadcast.</summary>
     [Fact]
     public void Heartbeat_updates_revision_in_next_snapshot()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/Harness/ControlPlaneTestHarness.cs

@@ -16,6 +16,7 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests.Harness;
 /// </summary>
 public abstract class ControlPlaneActorTestBase : TestKit
 {
+    /// <summary>Gets the Akka configuration for test actors, including cluster and pub-sub extensions.</summary>
     protected static string AkkaTestHocon => @"
 akka {
     loglevel = ""WARNING""
@@ -38,6 +39,7 @@ akka {
     }
 }";
 
+    /// <summary>Initializes a new instance of the test harness; joins the cluster and waits for up status.</summary>
     protected ControlPlaneActorTestBase() : base(AkkaTestHocon)
     {
         // Self-join so the cluster transitions to Up and DistributedPubSub forms.
@@ -47,6 +49,9 @@ akka {
             TimeSpan.FromSeconds(5));
     }
 
+    /// <summary>Creates a new in-memory database context factory with an optional database name.</summary>
+    /// <param name="dbName">Optional database name; defaults to a random GUID if not provided.</param>
+    /// <returns>A context factory for creating in-memory config database contexts.</returns>
     protected static IDbContextFactory<OtOpcUaConfigDbContext> NewInMemoryDbFactory(string? dbName = null)
     {
         dbName ??= Guid.NewGuid().ToString("N");
@@ -55,6 +60,8 @@ akka {
 
     private sealed class InMemoryConfigDbFactory(string dbName) : IDbContextFactory<OtOpcUaConfigDbContext>
     {
+        /// <summary>Creates a new in-memory database context.</summary>
+        /// <returns>A new OtOpcUaConfigDbContext instance.</returns>
         public OtOpcUaConfigDbContext CreateDbContext()
         {
             var opts = new DbContextOptionsBuilder<OtOpcUaConfigDbContext>()

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/RedundancyStateActorTests.cs

@@ -15,6 +15,7 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;
 /// </summary>
 public sealed class RedundancyStateActorTests : ControlPlaneActorTestBase
 {
+    /// <summary>Verifies that a self-join event triggers RedundancyStateChanged through the broadcast override.</summary>
     [Fact]
     public void Self_join_triggers_RedundancyStateChanged_via_broadcast_override()
     {
@@ -27,6 +28,7 @@ public sealed class RedundancyStateActorTests : ControlPlaneActorTestBase
         msg.CorrelationId.Value.ShouldNotBe(Guid.Empty);
     }
 
+    /// <summary>Verifies that multiple back-to-back events debounce to a single RedundancyStateChanged publication.</summary>
     [Fact]
     public void Multiple_back_to_back_events_debounce_to_single_publish()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/ServiceLevelCalculatorTests.cs

@@ -7,6 +7,8 @@ namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;
 
 public sealed class ServiceLevelCalculatorTests
 {
+    /// <summary>Verifies that non-Up member statuses return a service level of zero.</summary>
+    /// <param name="status">The Akka cluster member status to test.</param>
     [Theory]
     [InlineData(MemberStatus.Down)]
     [InlineData(MemberStatus.Removed)]
@@ -19,6 +21,7 @@ public sealed class ServiceLevelCalculatorTests
         sl.ShouldBe((byte)0);
     }
 
+    /// <summary>Verifies that a fully healthy non-leader member returns a service level of 240.</summary>
     [Fact]
     public void Fully_healthy_non_leader_returns_240()
     {
@@ -27,6 +30,7 @@ public sealed class ServiceLevelCalculatorTests
         sl.ShouldBe((byte)240);
     }
 
+    /// <summary>Verifies that a fully healthy role leader returns a service level of 250.</summary>
     [Fact]
     public void Fully_healthy_role_leader_returns_250()
     {
@@ -35,6 +39,7 @@ public sealed class ServiceLevelCalculatorTests
         sl.ShouldBe((byte)250);
     }
 
+    /// <summary>Verifies that a database reachable but stale returns a service level of 200.</summary>
     [Fact]
     public void Db_reachable_but_stale_returns_200()
     {
@@ -43,6 +48,7 @@ public sealed class ServiceLevelCalculatorTests
         sl.ShouldBe((byte)200);
     }
 
+    /// <summary>Verifies that an unreachable and stale database returns a service level of 100.</summary>
     [Fact]
     public void Db_unreachable_and_stale_returns_100()
     {
@@ -51,6 +57,7 @@ public sealed class ServiceLevelCalculatorTests
         sl.ShouldBe((byte)100);
     }
 
+    /// <summary>Verifies that an OPC UA probe failure on a non-stale database returns zero.</summary>
     [Fact]
     public void Opcua_probe_fail_when_not_stale_returns_zero()
     {
@@ -60,6 +67,7 @@ public sealed class ServiceLevelCalculatorTests
         sl.ShouldBe((byte)0);
     }
 
+    /// <summary>Verifies that a Joining member status is treated like Up for service level grading.</summary>
     [Fact]
     public void Joining_member_is_treated_like_Up_for_grading()
     {