5.68.0
(feat): Add an auto-generate-idempotency-key generator config key. When enabled, the
CLI records idempotency-key auto-generation in the IR (SdkConfig.idempotencyKeyGeneration)
so every generator reads a single, canonical setting from the IR instead of each
defining its own config key. Accepts true or { header-name: "Idempotency-Key" }
and is stripped from the config forwarded to generators.