Make one of a waiting plan's advised changes.

A waiting plan's advice is never a gate: the plan stays approvable either way. openingNovelty says when its opening echoes an earlier film of the same product and the one change that avoids it (alternative.field and alternative.value); signatureDeviceAgreement says which capture beats show a different device from the one the story's cast is always seen with (mismatchedBeatIds). Applying one changes only the beat it names and nothing else. Free. Send { kind: "opening", field, value } (from openingNovelty.alternative) or { kind: "device", beatIds } (from signatureDeviceAgreement.mismatchedBeatIds). Answers whether it changed anything and the advice after it. Naturally idempotent. The plan review card's button and Slug make the same change.