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-speechbubble/dees-speechbubble.ts

@@ -17,6 +17,7 @@ import {
   unsafeHTML,
 } from '@design.estate/dees-element';
 import { DeesWindowLayer } from '../dees-windowlayer/dees-windowlayer.js';
+import { themeDefaultStyles } from '../00theme.js';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -78,8 +79,10 @@ export class DeesSpeechbubble extends DeesElement {
   }
 
   public static styles = [
+    themeDefaultStyles,
     cssManager.defaultStyles,
     css`
+      /* TODO: Migrate hardcoded values to --dees-* CSS variables */
       :host {
         box-sizing: border-box;
         color: ${cssManager.bdTheme('#333', '#fff')};