Use semantic colors in themes (#5796)

Co-authored-by: Jacob Richman <jacob314@gmail.com>

packages/cli/src/ui/themes/github-dark.ts

@@ -5,6 +5,7 @@
  */
 
 import { type ColorsTheme, Theme } from './theme.js';
+import { darkSemanticColors } from './semantic-tokens.js';
 
 const githubDarkColors: ColorsTheme = {
   type: 'dark',
@@ -142,4 +143,5 @@ export const GitHubDark: Theme = new Theme(
     },
   },
   githubDarkColors,
+  darkSemanticColors,
 );