Add XML documentation across gateway, worker, and .NET client

src/MxGateway.Server/Security/Authentication/ApiKeyAdminParseResult.cs

@@ -5,16 +5,21 @@ public sealed record ApiKeyAdminParseResult(
     ApiKeyAdminCommand? Command,
     string? Error)
 {
+    /// <summary>Returns a result indicating the input was not an API key command.</summary>
     public static ApiKeyAdminParseResult NotApiKeyCommand()
     {
         return new ApiKeyAdminParseResult(false, null, null);
     }
 
+    /// <summary>Returns a successful parse result with the parsed API key command.</summary>
+    /// <param name="command">Parsed API key administration command.</param>
     public static ApiKeyAdminParseResult Success(ApiKeyAdminCommand command)
     {
         return new ApiKeyAdminParseResult(true, command, null);
     }
 
+    /// <summary>Returns a parse result with the specified error message.</summary>
+    /// <param name="error">Error message describing the parse failure.</param>
     public static ApiKeyAdminParseResult Fail(string error)
     {
         return new ApiKeyAdminParseResult(true, null, error);