Fix keyboard reliability

[cwervo]

The goal of this PR is twofold:

• make a tool that observes the underlying keyboard signals (e.g. reading /dev/input/by-path/keyboard-name manually in Tcl or C, or use evtest on it) and monitors if the associated Folk Claim is made. If it is made, track the delta (in milliseconds) for how long it takes to go from appearing in kernel event log → triggering in Folk
• in the process of making the above utility we'll discover bugs in this pipeline and/or bugs in how the Ctrl modifier keys are handled, allowing us to address Ctrl-S broken sometimes, just types 's' #163