Add odoc-spa-loaded event to docsite shell and scrollycode
- docsite shell: dispatch odoc-spa-loaded after SPA script loading,
matching the jon-shell implementation
- scrollycode: listen for odoc-spa-loaded to reinit after SPA nav
Plugins checked:
- mermaid: uses odoc-spa-loaded ✓
- dot: uses odoc-spa-loaded ✓
- msc: uses odoc-spa-loaded ✓
- scrollycode: uses odoc-spa-loaded ✓ (updated)
- admonition: CSS only, no JS needed ✓
- rfc: CSS only, no JS needed ✓
- interactive (x-ocaml): own universe reinit mechanism ✓
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>