Review follow-up: tests that monkeypatch CRON_DIR/JOBS_FILE/OUTPUT_DIR (the
documented process-wide compatibility surface) were bypassed by the lazy
env fallback — 3 file-permission tests, the cross-process lock test, and
the heartbeat roundtrip regressed. _current_cron_store() now snapshots the
constants at import and honors any deliberate re-point of them ahead of
the env resolution, so the precedence is: use_cron_store() override >
patched constants > fresh HERMES_HOME > import defaults. Adds a test
pinning constants-beat-env; the late-env sentinel behavior is unchanged.
tests/cron: failure set byte-identical to unpatched main on this box
(the 5 regressions gone); 138 pass in the touched files.
65d6bd2b9f