feat: add APIMart AI generation and guided Studio onboarding

app/lib/studio-guide.ts

@@ -0,0 +1,11 @@
+export const studioHelpScript = `window.addEventListener("error",function(){var s=document.getElementById("validation-state"),d=document.getElementById("diagnostics");if(s&&s.textContent==="Checking"){s.textContent="Editor could not start";if(d)d.textContent="Reload the page. If this continues, rebuild and restart the site with the latest Studio configuration. Your saved draft has not been deleted.";}});document.addEventListener("DOMContentLoaded",function(){var b=document.querySelector('[data-tab="guided"]');if(b)b.click();});`;
+
+export function addStudioGuide(html: string, configured: boolean) {
+  const guide = `<details open class="help"><summary><strong>How to use Design Studio</strong></summary><ol><li><strong>Describe your website.</strong> Open Guided design, enter your product and audience, then choose colors, shapes and spacing with Next.</li><li><strong>Generate and compare.</strong> Click Generate three directions, review an alternative, then choose Use reviewed proposal.</li><li><strong>Refine it.</strong> Try “make buttons square and use blue as the primary color” under Edit with words. Lock decisions you want to keep.</li><li><strong>Use it in your app.</strong> Open Review &amp; apply and export Theme config or Compiled CSS. This website previews and exports designs; it does not change your deployed app automatically.</li></ol><p>${configured ? "APIMart AI is enabled with gpt-6-luna. Generation sends your brief and current design to APIMart only when you request it." : "AI is not configured. Local presets and supported rule-based edits still work. Set APIMART_API_KEY in the server .env and restart to enable gpt-6-luna."}</p></details>`;
+  return html
+    .replace(
+      '<script type="module"',
+      '<script src="./site-help.js"></script><script type="module"',
+    )
+    .replace('<div id="diagnostics"', guide + '<div id="diagnostics"');
+}