Two mutation-testing survivors in scripts/redeploy-fleetd.sh: a source-text
test pins what a message SAYS but never whether the branch that prints it is
REACHED.
- Extract the drain-gate abort decision into drain_gate_refusal(do_build,
staged_path), a pure function the suite can call directly for all four
build/staged combinations. The existing source-text grep test is kept
alongside it (it catches a re-wording; the new tests catch a dead branch).
- Extend jar_id's test to cover the missing-file path (both the no-argument
default and an explicit path), which the #511 test never exercised.
Dai Ha