docs+ui: backfill XML doc comments and finish dashboard layout pass

Adds missing <summary>/<param> XML docs across 99 server, worker, and test
files so CommentChecker reports zero issues (TreatWarningsAsErrors needs the
analyzer clean). Bundles in WIP dashboard work: NavSection extraction,
MainLayout/site.css/js styling alignment, and DashboardOptions/Auth tweaks.

src/ZB.MOM.WW.MxGateway.Tests/Gateway/Workers/WorkerExecutableValidatorTests.cs

@@ -17,6 +17,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
 
     private readonly List<string> _tempFiles = [];
 
+    /// <summary>Verifies that x86 executable matching required architecture does not throw.</summary>
     [Fact]
     public void Validate_X86ExecutableMatchingRequiredArchitecture_DoesNotThrow()
     {
@@ -25,6 +26,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         WorkerExecutableValidator.Validate(path, WorkerArchitecture.X86);
     }
 
+    /// <summary>Verifies that x64 executable matching required architecture does not throw.</summary>
     [Fact]
     public void Validate_X64ExecutableMatchingRequiredArchitecture_DoesNotThrow()
     {
@@ -33,6 +35,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         WorkerExecutableValidator.Validate(path, WorkerArchitecture.X64);
     }
 
+    /// <summary>Verifies that x64 executable when x86 required throws invalid executable.</summary>
     [Fact]
     public void Validate_X64ExecutableWhenX86Required_ThrowsInvalidExecutable()
     {
@@ -45,6 +48,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         Assert.Contains("architecture", exception.Message, StringComparison.OrdinalIgnoreCase);
     }
 
+    /// <summary>Verifies that x86 executable when x64 required throws invalid executable.</summary>
     [Fact]
     public void Validate_X86ExecutableWhenX64Required_ThrowsInvalidExecutable()
     {
@@ -56,6 +60,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         Assert.Equal(WorkerProcessLaunchErrorCode.InvalidExecutable, exception.ErrorCode);
     }
 
+    /// <summary>Verifies that file without MZ header throws invalid executable.</summary>
     [Fact]
     public void Validate_FileWithoutMzHeader_ThrowsInvalidExecutable()
     {
@@ -70,6 +75,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         Assert.Contains("MZ", exception.Message, StringComparison.Ordinal);
     }
 
+    /// <summary>Verifies that file too small for PE header throws invalid executable.</summary>
     [Fact]
     public void Validate_FileTooSmallForPeHeader_ThrowsInvalidExecutable()
     {
@@ -81,6 +87,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         Assert.Equal(WorkerProcessLaunchErrorCode.InvalidExecutable, exception.ErrorCode);
     }
 
+    /// <summary>Verifies that file without PE signature throws invalid executable.</summary>
     [Fact]
     public void Validate_FileWithoutPeSignature_ThrowsInvalidExecutable()
     {
@@ -122,6 +129,7 @@ public sealed class WorkerExecutableValidatorTests : IDisposable
         return path;
     }
 
+    /// <inheritdoc />
     public void Dispose()
     {
         foreach (string path in _tempFiles)