Function createStatusReader

showcase/harness/src/orchestrator.ts:2057–2084

(pb: {
  getFirst<T>(collection: string, filter: string): Promise<T | null>;
})

 * without spinning up the full boot path.
 */
export function createStatusReader(pb: {
  getFirst<T>(collection: string, filter: string): Promise<T | null>;
}): {
  getStateByKey(key: string): Promise<State | null>;
} {
  return {
    async getStateByKey(key: string): Promise<State | null> {
      // Mirror alert-state-store's defense-in-depth: reject keys with
      // C0/C1 control chars BEFORE they reach PB's filter parser.
      // Today's probes only emit printable-ASCII keys, but a future
      // probe emitting a control char would throw at PB filter parse
      // time — the throw gets swallowed by dispatchCronAlert's wrapper
      // and the rule silently fails. `assertSafeKey` throws with a
      // clear message; callers see a specific failure rather than an
      // opaque PB DSL error.
      assertSafeKey("key", key);
      const row = await pb.getFirst<StatusRecord>(
        "status",
        `key = ${JSON.stringify(key)}`,
      );
      // A6(viii) (round 7): degrade-don't-trust, same as every other PB
      // state read. Returning `row?.state` RAW let a corrupt/legacy value
      // (anything outside green|red|degraded) flow into dispatchCronAlert's
      // synthesized WriteOutcome as a bogus prior state.
      return asKnownState(row?.state) ?? null;
    },
  };
}

/**
 * Project a per-cfg env overlay for `buildProbeInvoker`. Drivers that