I am looking for a headboard-attached swivel arm for a laptop, so I
can use the laptop while in bed, and then be able to quickly and
conveniently "push it away" when I'm done.

None of the swivel arms that I've seen online so far seem good enough.
They don't seem to be long enough. Also, The kind I need would
probably have to have at least 3 joints for proper positioning/
adjustment.

TIA