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-searchbar/dees-searchbar.ts

@@ -13,6 +13,7 @@ import {
 
 import * as colors from '../00colors.js';
 import { demoFunc } from './dees-searchbar.demo.js';
+import { themeDefaultStyles } from '../00theme.js';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -27,8 +28,10 @@ export class DeesSearchbar extends DeesElement {
 
   // STATIC
   public static styles = [
+    themeDefaultStyles,
     cssManager.defaultStyles,
     css`
+      /* TODO: Migrate hardcoded values to --dees-* CSS variables */
       :host {
         padding: 40px;
         font-family: Dees Sans;