verify 1.2.1

@missing-elements/h5p-verify 1.2.1. Nothing else changes: the player stays at 1.1.1, cmi5 at 1.1.0 and embed at 1.1.1.

Ctrl+C ends --preview with its closing line and exit code 0 when run through npx (#79)

Run through npx, as the docs show, one Ctrl+C reached the preview twice: the terminal sends it to the whole process group, and npm passes on its own copy. 1.2.0 stopped listening after the first, so the second killed it before it printed "The preview ended.", and it never exited with 0. The preview itself still stopped and freed its port.

The preview now listens for SIGINT and SIGTERM for as long as it runs, from before it prints its address. Measured with one Ctrl+C through npx, three runs each: 1.2.0 never printed the closing line and was killed by the signal; 1.2.1 printed it and exited with 0 every time.

An agent that leaves the preview to end when its tab closes sends no signal, and was not affected.

Upgrading

npx @missing-elements/h5p-verify@latest runs 1.2.1.

Full Changelog: verify-v1.2.0...verify-v1.2.1