Unexpected reload of Chrome extension written with PyScript

mark.d.lattimore: Below are the html and manifest files for a mortgage calculator extension (it is adapted from a PyScript webpage I wrote earlier). The pop-up provides fields for the user to enter details about a loan (loan amount, interest rate, term, etc.) and then on clicking the “Calculate Payment” button, is supposed to provide a payment breakdown. When run as a webpage, it performs exactly as expected.