Two notes after the deadline
1. A formatting fix. On 13 November we fixed a LaTeX/markdown formatting error in the "What it does" section. No content changed.
2. The Bryntum trial. FoldBack's live board uses the Bryntum Scheduler trial (v7.3.7). The trial ends around 12 December, during the judging period (1 to 15 December).
Bryntum announced a free Community version (v8) a few hours before the submission deadline, too late for us to switch and test safely. Since the Submission Period has ended, we are not changing the code or the deployed app.
If the board stops loading after 12 December, the demo video shows it working end to end, and the README explains how to run the project with a fresh trial install. Everything else (reading the plan, PayPal sandbox holds, capture and release) does not depend on Bryntum.