Ticking "select all" disabled every keyboard shortcut until the reader clicked
somewhere else (#260). Same for the per-message checkboxes, so selecting a few
messages and pressing e to archive them did nothing.
The guard that stops "a" archiving while you are typing into the search box
tested `tagName === "INPUT"`. That is also true of a checkbox, and a checkbox
keeps focus after a click -- correctly, since space should toggle it again.
So the guard was suppressing shortcuts for an element that swallows no
keystroke: space is handled by the browser before this listener runs.
The question is not "is this an input" but "does this input take text", which
is what isTextEntry now asks. A <select> counts, in the sense that matters
here: typing a letter jumps to the option starting with it, and a shortcut
would steal that.
Thirteen checkboxes and seven file inputs across the app were affected, not
just the one reported.
The regression test was checked against the old guard first: it fails there
and passes here, which is the only thing that makes it a regression test.
