Cache Control Integration 5.3

Fixed: Strengthened cache purge authorization, site validation, mixed-result reporting, and bulk-run reliability.

Fixed: Reading a Cloudflare key saved by an older extension version no longer deletes it during migration to encrypted storage, and bearer token reads leave the stored key untouched.

Fixed: A failed credential save or delete can no longer leave the stored Cloudflare key or token undecryptable; the old key file is kept until the new value is confirmed stored.

Fixed: Bulk purge runs keep per-site results separate and keep retry available after mixed or failed outcomes.

Added: Site cache status ability for the MainWP Abilities API, reporting a child site's detected cache solution, last reported purge, and auto-purge configuration.

Updated: Improved Cloudflare enablement handling when no applicable settings are configured.