v1.3.0 Restructure Saxonite workspace and upgrade to .NET 10 (#1)

Move Saxonite’s projects into a dedicated `Workspace` folder and align the solution with .NET 10 and the current Common workspace. Update encryption integration, test project structure and coverage, and repository guidance and upgrade notes.

- Relocate application and library projects while retaining Git rename history.
- Split tests into Admin, Online, and Shared projects; add representative behavioral and serialization tests.
- Update Common integration, application version, and repository documentation.

Application version: 1.3.0

Reviewed-on: #1
Co-authored-by: andy <andy@sarand.com>

Workspace/SaxoniteStandardBase/Base/Bus/SaxDisposableHierarchyItem.cs

@@ -0,0 +1,17 @@
+using Sarand.Net.Standard.Base.Bus;
+using Sarand.Net.Standard.Base.Core;
+using System;
+
+namespace Saxonite.Net.Standard.Base.Bus
+{
+	//=======================================================================
+	/// <summary>Preserves Saxonite's disposable hierarchy-item contract over Common hierarchy items.</summary>
+	public abstract class SaxDisposableHierarchyItem : SacsHierarchyItem, IDisposable
+	{
+		protected SaxDisposableHierarchyItem() : base() { }
+		protected SaxDisposableHierarchyItem(SysId id) : base(id) { }
+
+		public void Dispose() { }
+	}
+	//=======================================================================
+}