fix(CssManager): Make CssManager a singleton and export the shared instance via getSingleton; update tests and dependencies

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@design.estate/dees-element',
-  version: '2.1.2',
+  version: '2.1.3',
   description: 'A library for creating custom elements extending the lit element class with additional functionalities.'
 }

ts/classes.cssmanager.ts

@@ -9,6 +9,21 @@ export interface IBdVarTriplet {
 }
 
 export class CssManager {
+  // STATIC
+  private static instance: CssManager | null = null;
+
+  /**
+   * Returns the singleton instance of CssManager
+   */
+  public static getSingleton(): CssManager {
+    if (!CssManager.instance) {
+      CssManager.instance = new CssManager();
+    }
+    return CssManager.instance;
+  }
+
+  
+  // INSTANCE
   public domtoolsPromise = domtools.DomTools.setupDomTools();
   public goBright: boolean = false;
   public bdVarTripletStore: IBdVarTriplet[] = [];

ts/index.ts

@@ -26,7 +26,7 @@ export { directives };
 /**
  * a singleton instance of CssManager
  */
-export const cssManager = new CssManager();
+export const cssManager = CssManager.getSingleton();