How do I assign an input video's framerate to the output video when multiple input arguments are present?
-framerate is an input option for image sequence input, so it goes before that input.

Here's the combined command:

ffmpeg -framerate 30 -i edited%05d.png -i in.webm -c:v libvpx-vp9 -pix_fmt yuva420p -lossless 1 -c:a copy out.webm