Asynchronous WordPress Link Scanner

I need a compact, production-ready WordPress plugin that scans posts, pages, and any registered custom post type for broken internal links only. The checker must hit the usual HTTP status codes—200, 301, 404, 500—and flag redirects while making sure the same URL is never tested twice. All network activity has to run through asynchronous, non-blocking requests so the front-end remains untouched and PHP time-outs are a non-issue on sites with tens of thousands of records.

Inside the admin you’ll surface a lightweight dashboard that shows a basic summary of error counts per status, offers one-click manual re-scans, and stores a concise scan history. WP-Cron should trigger scheduled scans at an interval I can adjust, and there must be a simple “ignore” toggle so I can exclude specific links from future passes.

Because efficiency is paramount, please think through transient caching, chunked queries, and anything else that prevents duplicate HTTP calls while keeping memory usage low. I should be able to install, activate, and let it run without additional setup; no third-party services or API keys.

Deliverables I will use for acceptance:
• Fully documented, namespaced plugin folder ready to drop into /wp-content/plugins
• Admin UI with summary counts, manual recheck button, and scan history table
• Cron-based scheduler, async link crawler, duplicate-URL suppression, ignore list
• Clean, commented code that passes WordPress Coding Standards

If this sounds like your sort of challenge, let’s get it done.