User reports window opens too stretched

> When the pop-up window opens it stretches so much that I can't even reach the titlebar in order to resize the window. Can't even close. In my option the default window size should be lower window size and you could also give us the option to open it by default in the sidebar

\- Firefox Add-on user

Start by reproducing the oversized popup in Firefox and locate the browser-extension entry point that creates or sizes the Google Tasks window. The issue requests a smaller default window and an option to open Google Tasks in the sidebar; confirm the intended behavior and platform support before considering the work done.

Written by the indexing model from the issue text.