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/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()
     {