Function diffCronSchedules

showcase/harness/src/orchestrator.ts:2149–2243

(
  scheduler: ReturnType<typeof createScheduler>,
  rules: CompiledRule[],
  bus: ReturnType<typeof createEventBus>,
  cronProbeResolver: CronProbeResolver,
)

 * RAILWAY_PROJECT_ID, RAILWAY_ENVIRONMENT_ID, AIMOCK_URL).
 */
export async function diffCronSchedules(
  scheduler: ReturnType<typeof createScheduler>,
  rules: CompiledRule[],
  bus: ReturnType<typeof createEventBus>,
  cronProbeResolver: CronProbeResolver,
): Promise<void> {
  const desired = new Map<
    string,
    { schedule: string; ruleId: string; dimension: string }
  >();
  for (const r of rules) {
    for (const [idx, cron] of r.cronTriggers.entries()) {
      const id = `${r.id}:cron:${idx}`;
      desired.set(id, {
        schedule: cron.schedule,
        ruleId: r.id,
        dimension: r.signal.dimension,
      });
    }
  }
  const currentIds = scheduler.list().map((e) => e.id);
  for (const id of currentIds) {
    if (!desired.has(id) && id.includes(":cron:")) {
      // R2-B.1: await the unregister, mirroring the CR-A2.2 fix on the
      // probe-rule path. Pre-fix this was fire-and-forget — a rejection
      // became an unhandled rejection AND the orphan got no structured
      // log. On rejection we log (operators get a first-class signal)
      // and leave the entry in scheduler.list(); next diff sweep will
      // retry. Same design choice as CR-A2.2: the orphan stays VISIBLE
      // rather than being silently dropped from bookkeeping.
      try {
        await scheduler.unregister(id);
      } catch (err) {
        logger.error("orchestrator.cron-unregister-failed", {
          id,
          err: String(err),
        });
        // R2-B.4: dedicated `scheduler_unregister_failures_total` counter
        // would belong here, but adding it requires extending metrics.ts
        // COUNTER_NAMES (out of scope for this fix). Defer to bucket-b
        // follow-up; the structured log above is the first-class
        // observability surface in the meantime.
      }
    }
  }
  for (const [id, { schedule, ruleId, dimension }] of desired) {
    const invoker = cronProbeResolver(dimension);
    // A2: wrap `scheduler.register` per-rule so a single typoed cron
    // expression (validateCron throws synchronously inside register())
    // does NOT poison the rest of the reload. Pre-fix, one bad rule
    // aborted the for-loop → every subsequent rule silently unscheduled.
    // Pinned by the "continues registering subsequent rules" regression
    // test in orchestrator.test.ts — do not remove without updating it.
    try {
      scheduler.register({
        id,
        cron: schedule,
        handler: async () => {