Add a one-time, dismissible admin notice for sites upgrading from the
classic (pre-12) plugin: confirms existing iframe embeds keep working and
points to the new block. Shown only when classic data is detected.
Add an “Upgrading from the classic version?” FAQ entry.
12.0.0
Complete rewrite for SpreadsheetConverter v12.
Gutenberg block with inline (no-iframe) rendering via the <ssc-calc>
embed mount.
Self-host mode: block-initiated pull — WordPress fetches the calculator
bundle server-side; no credentials, no CORS.
Cloud-link mode: reference a permanent Publish-to-Cloud URL.
Manual zip upload fallback for air-gapped hosts.
[ssc_calc] shortcode for classic themes.
Removed: custom post type, upload-triggered ZIP extraction, version
regex, debug file logging, TinyMCE iframe inserter.
