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/Core/ZB.MOM.WW.OtOpcUa.Core.ScriptedAlarms.Tests/ScriptedAlarmSourceTests.cs

@@ -40,6 +40,7 @@ public sealed class ScriptedAlarmSourceTests
         return (engine, source, up);
     }
 
+    /// <summary>Verifies that subscribing with an empty filter receives every alarm emission.</summary>
     [Fact]
     public async Task Subscribe_with_empty_filter_receives_every_alarm_emission()
     {
@@ -64,6 +65,7 @@ public sealed class ScriptedAlarmSourceTests
         await source.UnsubscribeAlarmsAsync(handle, TestContext.Current.CancellationToken);
     }
 
+    /// <summary>Verifies that subscribing with an equipment prefix filters alarms by that prefix.</summary>
     [Fact]
     public async Task Subscribe_with_equipment_prefix_filters_by_that_prefix()
     {
@@ -86,6 +88,7 @@ public sealed class ScriptedAlarmSourceTests
         await source.UnsubscribeAlarmsAsync(handle, TestContext.Current.CancellationToken);
     }
 
+    /// <summary>Verifies that unsubscribing stops further alarm events.</summary>
     [Fact]
     public async Task Unsubscribe_stops_further_events()
     {
@@ -104,6 +107,7 @@ public sealed class ScriptedAlarmSourceTests
         events.Count.ShouldBe(0);
     }
 
+    /// <summary>Verifies that AcknowledgeAsync routes to the engine with a default user.</summary>
     [Fact]
     public async Task AcknowledgeAsync_routes_to_engine_with_default_user()
     {
@@ -125,6 +129,7 @@ public sealed class ScriptedAlarmSourceTests
         state.LastAckComment.ShouldBe("ack via opcua");
     }
 
+    /// <summary>Verifies that null arguments are rejected.</summary>
     [Fact]
     public async Task Null_arguments_rejected()
     {