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-windowcontrols/dees-windowcontrols.ts

@@ -10,6 +10,7 @@ import {
   css,
   cssManager,
 } from '@design.estate/dees-element';
+import { themeDefaultStyles } from '../00theme.js';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -34,8 +35,10 @@ export class DeesWindowControls extends DeesElement {
   accessor position: 'left' | 'right' = 'left';
 
   public static styles = [
+    themeDefaultStyles,
     cssManager.defaultStyles,
     css`
+      /* TODO: Migrate hardcoded values to --dees-* CSS variables */
       :host {
         position: relative;
         display: block;