Activate — pin this schedule's revision/page/recipients/cadence under the shared dispatcher (DVT-4794, ADR-0069 Amendment 5).

A ROW WRITE, not Snowflake DDL: pins the dashboard's LATEST revision, the schedule's page scope, its current (active) recipients and its cadence, and sets the driver to the shared dispatcher — the terms a later dispatcher run plans and sends from, independent of any live edit made after this call. No engine call, no caller token, no warehouse. Re-activating an already-activated (or legacy) row re-pins it from scratch.

Requires dashboard:write on the dashboard AND the schedule:activate capability (D8, admin-ranked — not dashboard ownership: a dashboard owner who is merely an editor org-wide is still refused 403). Same 404-feature-disabled gate as the rest of this group.

Refuses 422 schedule-activation-failed with a blocker extension (one of cadence-too-fine, disabled, no-recipients, bad-timezone, page-missing — the same vocabulary GET .../activation's blockers[] reports) when the schedule is disabled, has no recipients, its timezone cannot be resolved, or its page scope no longer exists in the revision being pinned. 409 schedule-activation-failed when the activating actor is a soft-deleted user or no longer a member of this organization.

A LEGACY per-report task (taskState other than absent from before this schedule was ever activated this way) is retired, not touched in Snowflake: the response's retiredTaskName names the deterministic task an admin can now DROP TASK.