feat(website): serve /llms.txt and raw markdown for docs

Adds an llms.txt at the site root with a static product preamble so
LLMs can answer "what is Paseo" without following any links, plus a
curated index of docs, alternatives, and the 38 agent pages. Doc pages
now expose Copy/View as markdown buttons and a raw .md version at
<path>.md following the llms.txt convention.

Also skips the canonical-host redirect for localhost so the dev server
stops punting every request to production.

packages/website/src/routes/docs/$.tsx

@@ -1,5 +1,6 @@
 import { createFileRoute } from "@tanstack/react-router";
 import { DocsMarkdown } from "~/components/docs-markdown";
+import { DocsMarkdownActions } from "~/components/docs-markdown-actions";
 import { DocsSourceFooter } from "~/components/docs-source-footer";
 import { getDoc } from "~/docs";
 import { pageMeta } from "~/meta";
@@ -30,6 +31,7 @@ function RenderedDoc({ slug }: { slug: string }) {
 
   return (
     <>
+      <DocsMarkdownActions content={doc.content} markdownHref={`/docs/${slug}.md`} />
       <DocsMarkdown>{doc.content}</DocsMarkdown>
       <DocsSourceFooter doc={doc} />
     </>

packages/website/src/routes/docs/index.tsx

@@ -1,5 +1,6 @@
 import { createFileRoute } from "@tanstack/react-router";
 import { DocsMarkdown } from "~/components/docs-markdown";
+import { DocsMarkdownActions } from "~/components/docs-markdown-actions";
 import { DocsSourceFooter } from "~/components/docs-source-footer";
 import { getDoc } from "~/docs";
 import { pageMeta } from "~/meta";
@@ -23,6 +24,7 @@ function DocsIndex() {
   if (!doc) return <p className="text-muted-foreground">Doc not found.</p>;
   return (
     <>
+      <DocsMarkdownActions content={doc.content} markdownHref="/docs.md" />
       <DocsMarkdown>{doc.content}</DocsMarkdown>
       <DocsSourceFooter doc={doc} />
     </>