HEEx components for the DemoDirector overlay.

Mount once on a layout (typically the dev-time root layout):

import DemoDirector.Components

~H"""
<.demo_director_overlay />
"""

When the host app's router has called demo_director/1 (the macro from DemoDirector.Router), this component renders:

• a <link rel="stylesheet"> pointing at the macro-mounted CSS
• a <script> pointing at the matching JS
• the subtitle and highlight DOM nodes the agent's emitted JS will manipulate

When the macro has NOT been called (e.g., a prod build that gates the macro behind :dev_routes), the component renders nothing. This is the belt-and-suspenders strip — even if a layout accidentally calls the component in prod, it stays inert.