fix(llms): give llms.txt absolute links on the requesting origin (#27)

The index linked pages root-relatively, so a copy of llms.txt handed to a
model or fetched on its own pointed nowhere. Build each link from the
request's origin instead, which keeps the repository free of channel
hostnames and serves every channel its own links.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: zfy0701

app/llms.txt/route.ts

@@ -2,11 +2,10 @@ import { llms } from 'fumadocs-core/source'
 import { BASE_PATH } from '@/base-path.mjs'
 import { reference, source } from '@/lib/source'
 
-export const dynamic = 'force-static'
-
-// The llms.txt index: every guide and API operation with its URL, which page URLs give without the base path.
-export async function GET() {
+// The llms.txt index: every guide and API operation with an absolute URL on the origin it was requested from.
+export async function GET(request: Request) {
   const [guides, api] = await Promise.all([llms(source).index(), llms(reference).index()])
-  const body = `# AgentConnect\n\n${guides}\n\n${api}\n`.replaceAll('](/', `](${BASE_PATH}/`)
+  const root = `${new URL(request.url).origin}${BASE_PATH}`
+  const body = `# AgentConnect\n\n${guides}\n\n${api}\n`.replaceAll('](/', `](${root}/`)
   return new Response(body, { headers: { 'content-type': 'text/plain; charset=utf-8' } })
 }