Both installers generated the ledmatrix_web rules and copied them straight
into /etc/sudoers.d without ever parsing them. Every rule is built from
`which` lookups, so an empty or surprising path produces a malformed
drop-in -- and a malformed file in /etc/sudoers.d makes sudo refuse every
command for every user. On a headless Pi that is unrecoverable over SSH.
first_time_install.sh now runs `visudo -c` on the generated file and, if it
does not parse, prints what visudo said and leaves the installed file
untouched rather than replacing it with a broken one. configure_web_sudo.sh
does the same before it offers the rules for confirmation.
first_time_install.sh also built the file at a fixed /tmp path as root;
mktemp now picks the name.
test/test_sudoers_is_validated.py renders the installer's own sudoers
heredoc and checks the result with visudo -- the check neither installer
had -- and asserts the install stays gated on it.
Claude-Session: https://claude.ai/code/session_01Dby94z9PV3zVM25fqGNXTt
Co-authored-by: Claude <noreply@anthropic.com>
