prepareConfigPromotion

Deploy scope. Prepare a 15-minute reviewed promotion of the CONFIGURATION of a source environment into this (target) environment of the same project: the environment variable group plus each paired component's user variables (components pair by name, exactly like image promotion). The review buckets NAMES only — same, different, only_in_source, only_in_target — never a value; secret group values travel inside the sealed payload and are re-sealed under the target group on apply. 201 with promotion_id (cpro_...) and review_digest. At most 20 pending reviews per account.