Fix Open with AI button to include current URL in prompt (#189)

The AI prompt now embeds the current page URL so the agent can fetch
the page content directly (either the .md file for doc pages or the
page itself for API pages). Also references llms.txt for API pages
so agents have a site overview fallback. Markdown is always copied
to clipboard as a convenience backup.

Co-authored-by: Britton Hayes <brittonhayes@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: brittonhayes

src/components/AiContextMenu/index.tsx

@@ -204,23 +204,17 @@ export default function AiContextMenu(): JSX.Element {
 
   function buildAiUrl(baseUrl: string, queryParam: string): string {
     const mdUrl = getMarkdownUrl();
-    const pageTitle = document.querySelector("h1")?.textContent || document.title;
-    if (mdUrl) {
-      const prompt = `Read from ${mdUrl} so I can ask questions about it.`;
-      return `${baseUrl}?${queryParam}=${encodeURIComponent(prompt)}`;
-    }
-    // For API pages without .md files, copy content and prompt to paste
-    const prompt = `I have a page from the D&D 5e SRD API documentation: "${pageTitle}". The content is in my clipboard. I'll paste it so you can help me with questions about it.`;
+    const pageUrl = window.location.href;
+    const prompt = mdUrl
+      ? `Fetch ${mdUrl} and read the documentation so I can ask questions about it. The page is located at ${pageUrl}`
+      : `Fetch ${pageUrl} and read the page content so I can ask questions about this D&D 5e SRD API documentation. You can also fetch https://5e-bits.github.io/docs/llms.txt for a site overview.`;
     return `${baseUrl}?${queryParam}=${encodeURIComponent(prompt)}`;
   }
 
   async function handleOpenInAi(item: { id: string; url: string }) {
-    const mdUrl = getMarkdownUrl();
-    // Copy markdown to clipboard for API pages (no .md file) or as fallback
-    if (!mdUrl) {
-      const md = getPageMarkdown();
-      await navigator.clipboard.writeText(md);
-    }
+    // Always copy markdown to clipboard as a fallback
+    const md = getPageMarkdown();
+    await navigator.clipboard.writeText(md);
 
     let finalUrl: string;
     if (item.id === "claude") {