feat(theme,interfaces): Introduce a global theming system and unify menu/tab interfaces; migrate components to use themeDefaultStyles and update APIs accordingly

ts_web/elements/dees-updater/dees-updater.ts

@@ -11,6 +11,7 @@ import { demoFunc } from './dees-updater.demo.js';
 
 import '../dees-windowlayer/dees-windowlayer.js';
 import { css, cssManager } from '@design.estate/dees-element';
+import { themeDefaultStyles } from '../00theme.js';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -44,8 +45,10 @@ export class DeesUpdater extends DeesElement {
   }
 
   public static styles = [
+    themeDefaultStyles,
     cssManager.defaultStyles,
     css`
+      /* TODO: Migrate hardcoded values to --dees-* CSS variables */
       .modalContainer {
         will-change: transform;
         position: relative;