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.Security.Tests/JwtTokenServiceTests.cs

@@ -20,12 +20,14 @@ public sealed class JwtTokenServiceTests
             ExpiryMinutes = expiryMinutes,
         }), NullLogger<JwtTokenService>.Instance);
 
+    /// <summary>Verifies that a short signing key throws InvalidOperationException.</summary>
     [Fact]
     public void Short_signing_key_throws()
     {
         Should.Throw<InvalidOperationException>(() => NewService("too-short"));
     }
 
+    /// <summary>Verifies that issued tokens validate and preserve claims.</summary>
     [Fact]
     public void Issue_then_validate_roundtrips_claims()
     {
@@ -40,6 +42,7 @@ public sealed class JwtTokenServiceTests
             .Select(c => c.Value).ShouldBe(new[] { "ReadOnly", "AlarmAck" }, ignoreOrder: true);
     }
 
+    /// <summary>Verifies that tampered tokens are rejected during validation.</summary>
     [Fact]
     public void Tampered_token_is_rejected()
     {
@@ -55,6 +58,7 @@ public sealed class JwtTokenServiceTests
         principal.ShouldBeNull();
     }
 
+    /// <summary>Verifies that expired tokens are rejected during validation.</summary>
     [Fact]
     public void Expired_token_is_rejected()
     {
@@ -66,6 +70,7 @@ public sealed class JwtTokenServiceTests
         principal.ShouldBeNull();
     }
 
+    /// <summary>Verifies that tokens signed with a different key are rejected.</summary>
     [Fact]
     public void Cross_key_token_is_rejected()
     {