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-terminal/dees-terminal.ts

@@ -13,6 +13,7 @@ import * as webcontainer from '@webcontainer/api';
 
 import { Terminal } from 'xterm';
 import { FitAddon } from 'xterm-addon-fit';
+import { themeDefaultStyles } from '../00theme.js';
 
 declare global {
   interface HTMLElementTagNameMap {
@@ -57,8 +58,10 @@ export class DeesTerminal extends DeesElement {
   }
 
   public static styles = [
+    themeDefaultStyles,
     cssManager.defaultStyles,
     css`
+      /* TODO: Migrate hardcoded values to --dees-* CSS variables */
       :host {
         padding: 20px;
         background: var(--dees-terminal-background, #000000);