2.9.2 - Inline page linking & page un-deleting

Added

• Added a page that lists recently-deleted pages and allows users to undelete them for a limited time
• Added inline linking to content pages to all text fields
• Added a per-page cache for frequently-used page data

Changed

• Upgraded to the heroku-18 stack
• Optimized a ton of queries around the site, bringing page load speeds significantly down
• Page text fields now are full-width and expand when focused

Fixed

• Fixed contributor invitations sometimes not sending
• Fixed a bug preventing some users from viewing a universe's dedicated content list pages
• Fixed a bug preventing some users from viewing their recently-edited content list
• Fixed a bug that resulted in user profiles throwing 404 errors after deleting a page
• Fixed field placeholder text
• Fixed a few 500 errors in niche situations