Add CacheFirstHooksRegistrar that fires roi_theme_before_page_serve
hook on template_redirect priority 0 for singular pages.
- Only fires for anonymous users (cache doesn't apply to logged in)
- Only fires for singular pages (posts, pages, CPTs)
- Provides post_id to external plugins
- Does NOT define DONOTCACHEPAGE (allows page caching)
Plan 1000.01 implementation.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
ff5ba25505