feat: add modular web UI features

- Enable `web` command to start UI server
- Centralize web server setup and static serving
- Implement modular UI for chat and script editor
- Refactor Heroprompt UI into its own module
- Introduce dynamic theme switching and mobile menu

cli/hero.v

@@ -85,7 +85,7 @@ fn do() ! {
 	herocmds.cmd_git(mut cmd)
 	herocmds.cmd_generator(mut cmd)
 	herocmds.cmd_docusaurus(mut cmd)
-	// herocmds.cmd_web(mut cmd)
+	herocmds.cmd_web(mut cmd)
 
 	cmd.setup()
 	cmd.parse(os.args)