v1.2.0: Add SiteSEO module

What's New

• SiteSEO module — 4 new REST API endpoints for managing SiteSEO metadata:
  • GET /siteseo/post/{id} — Read all SEO meta for a post/page
  • POST /siteseo/post/{id} — Update SEO meta for a post/page
  • GET /siteseo/audit — Bulk audit SEO coverage across the site
  • GET /siteseo/settings — Read global SiteSEO configuration

Auto-discovered by the module loader when SiteSEO is active — no changes to existing files needed.