Salvaged from PR #57342 by @liuhao1024 (with the injection-scan half
from PR #57360 by @ghedeselmabot): cronjob(action='run', prompt=...)
silently discarded the prompt argument — per-run context never
reached the spawned cron session.
The prompt is now threaded as extra_prompt through the whole chain
(cronjob run action → _try_dispatch_background_run/_execute_job_now →
_run_claimed_job → run_one_job → run_job → _build_job_prompt) and
appended to the stored prompt under a '## Run Context' header for
that single fire only — never persisted to the job definition. It
passes the same strict _scan_cron_prompt injection scan as stored
prompts before firing, and works identically on the background and
sync fallback paths.
Test fakes across tests/cron/ updated to accept the new kwargs
(sibling-test blast radius from the signature change).
Co-authored-by: liuhao1024 <liuhao1024@users.noreply.github.com>
The scheduler's pre-dispatch loop called advance_next_run per due job —
one full load_jobs() + one full save_jobs() of the jobs file each — so
N due jobs cost N reads + N writes of the whole file (gateway-restart
catch-up or co-scheduled bursts). advance_next_runs() does one load +
at most one save for the whole due set with identical per-job semantics;
advance_next_run() is now a thin wrapper over it.
Measured (50 due recurring jobs, real jobs file): 107.9 ms -> 2.5 ms
(45x; 50 loads + 50 saves -> 1 + 1).
Tests: batch advances recurring and skips one-shots, single load + save
I/O pin (fails pre-fix — no such function), no save when nothing
advances, and per-job wrapper semantics unchanged. Related: #60946 and
#75833 both restructure this loop's call site for correctness — neither
addresses the I/O cost, and this batch primitive composes with either
dispatch design; happy to rebase onto whichever lands first.