refactor: collapse describe-run-warn idiom into run_task helper

The installer announced, ran, and warned on each operation with a
hand-written two-line pair, repeated ~35 times:

    action="enabling rngd service" && display "task" "$action"
    systemctl enable rngd >> "$logfile" 2>&1 || error_warn "$action" "$?"

I added a run_task "desc" cmd... helper that does this in one line, plus an
enable_service wrapper for the canonical "enabling <unit> service" case. The
35 single-command sites now call run_task. The three exact-wording service
enables (rngd, upower, fail2ban) use enable_service. Multi-line sites
(heredocs, subshells, intervening logic) keep the explicit form.

Behavior is unchanged: same descriptions, same commands, same logfile
redirection, same non-fatal warning on the real exit code. tests/run-task
covers the helper across Normal/Boundary/Error including exit-code
propagation, and the full unit suite stays green.

0 files changed, 0 insertions, 0 deletions