e2e-tests often fail because keyboard inputs are lost

Examples:
* The return key is lost when confirming the password: #1413
* The "Run a command" dialog doesn't open even though Alt+F2 was pressed:
* https://authd-e2e-test-logs.adrian-dombeck.workers.dev/pr-1455/run-24468049731-1/devel-authd-google/log.html#s1-s11-t1-k3-k1-k2

We should consider using the keyboard as little as possible, and running commands via ssh instead when possible. If we do have to use the keyboard, we should check if the inputs were recognized and repeat them if not.

Start by reproducing the lost Return key case in #1413 and the Alt+F2 failure shown in the linked e2e test log. Trace the e2e keyboard-input entry points and determine where SSH can replace keyboard use; done means commands and confirmations succeed reliably, with missed inputs detected and retried when keyboard use remains necessary.

Written by the indexing model from the issue text.