Serve a public landing page at / with buttons to the docs, GitHub repo,
Terms, Privacy and the admin login. Relocate the Nuxt admin console from
/ to /admin so the root is no longer the private console.
- add home-routes.ts (bilingual landing, auto dark mode, configurable
DOCS_URL / GITHUB_REPO_URL) mounted at /
- move console to admin/pages/admin.vue; redirect / and unknown SPA
routes to /admin
- point admin login/logout redirects at /admin
