Ensure schedule (config-as-code converge)

Idempotently converge a repo-defined schedule on a standalone flow or agent. Identity is name + target + account scope; the target may name the flow or agent instead of carrying its id, so one definition works in every environment. Hash-only probes skip the payload in the steady state (a miss is a normal 200 definitionRequired response); full requests create the schedule or update it when the canonical content hash differs. Set dryRun to plan without writing (CI drift gate) and onConflict: “overwrite” to converge over dashboard/API edits. Omit enabled to leave a paused schedule paused. Ensure never deletes; schedules owned by a product surface are never matched.