feat: add sitemap.xml and robots.txt for SEO

- Add @nuxtjs/sitemap module (auto-generates from all routes)
- Add robots.txt with sitemap reference
- site.url already configured, sitemap picks it up automatically

Closes #11

Author: bm-clawd

nuxt.config.ts

@@ -1,5 +1,6 @@
 export default defineNuxtConfig({
   extends: ['docus'],
+  modules: ['@nuxtjs/sitemap'],
   compatibilityDate: '2025-07-15',
   app: {
     head: {

package-lock.json

@@ -9,6 +9,7 @@
     "start": "node .output/server/index.mjs"
   },
   "dependencies": {
+    "@nuxtjs/sitemap": "^7.6.0",
     "beautiful-mermaid": "^0.1.3",
     "better-sqlite3": "^12.5.0",
     "docus": "latest",

package.json

@@ -0,0 +1,4 @@
+User-agent: *
+Allow: /
+
+Sitemap: https://docs.basicmemory.com/sitemap.xml