feat: body links, outbound rules and image attributes in the post body

- renderJournalBody runs the UI-SPEC L7 order on the sanitized body:
  h1 demotion, the CMS phrase auto-links, the outbound rules and lazy,
  async images, with vue-seo-layer's autolink, applyOutbound and
  imageAttrs; PostBody feeds it the page's resolve answer (autolinks,
  autolink_max, outbound, url) and the seo.links.newTabHint option
- the sanitizer keeps a link rel of only nofollow, sponsored and ugc
  (the Blog Editor's link form, as the Journal plugin's policy does);
  target is never kept, the outbound rules add it
- editor-corpus.json copied again from sm-journal-plugin (link-rel and
  image-decorative entries)
- smoke:ssr script; expectations for auto-links, both new-tab modes and
  the hint switched off

package.json

@@ -8,6 +8,7 @@
     "dev": "nuxi dev .playground",
     "build:playground": "nuxt build .playground",
     "test": "node --test --test-reporter=tap tests/*.test.ts",
+    "smoke:ssr": "node testing/smoke-ssr.mjs --output .playground/.output --fixtures testing/fixtures/acme --expect testing/expect-acme.txt && node testing/smoke-ssr.mjs --output .playground/.output --fixtures testing/fixtures/acme --expect testing/expect-acme-hint-off.txt --env NUXT_PUBLIC_SEO_LINKS_NEW_TAB_HINT=false",
     "dev:prepare": "nuxt prepare .playground",
     "check:git-install": "bash scripts/check-git-install.sh"
   },