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/00group-input/dees-input-checkbox/dees-input-checkbox.ts

@@ -9,6 +9,7 @@ import {
 import { DeesInputBase } from '../dees-input-base/dees-input-base.js';
 import { demoFunc } from './dees-input-checkbox.demo.js';
 import { cssGeistFontFamily } from '../../00fonts.js';
+import { themeDefaultStyles } from '../../00theme.js';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -38,9 +39,11 @@ export class DeesInputCheckbox extends DeesInputBase<DeesInputCheckbox> {
   }
 
   public static styles = [
+    themeDefaultStyles,
     ...DeesInputBase.baseStyles,
     cssManager.defaultStyles,
     css`
+        /* TODO: Migrate hardcoded values to --dees-* CSS variables */
         * {
           box-sizing: border-box;
         }