Linkable

Keyword management:
* Keywords are stored per post and per page as JSON in the linkable_tags post meta field
* linkable_tags is registered with REST support, sanitized via sanitize_text_field, and restricted to users with edit_posts

Settings:
* Accessible via Settings → Linkable
* max_links_per_target: limits how many times the same target can be linked from one post (default 1)
* first_occurrence_only: when enabled, each keyword is linked only once per post

Performance:
* Builds a global keyword map from all published posts and pages with linkable_tags
* Caches the keyword map with a transient (global_linkable_tag_map) for one hour
* Query optimized to fetch only IDs and avoid unnecessary meta/term caching

Editor compatibility:
* Works with both the block editor and the classic editor
* Enqueues an admin sidebar panel script (static/js/admin-sidebar-panel.js) with WordPress dependencies and versioning via filemtime

Security:
* URLs are properly escaped with esc_url
* Link titles are sanitized and HTML-escaped
* Meta registration includes capability and sanitization checks

License

This plugin is licensed under the GPLv2 or later.