fn_task_promote can now pass force:true to start execution when a task is still
waiting on planning or plan review, matching the dashboard's promote override.
The rejection message names the flag so a caller that hits the gate can decide,
and a forced release says the pending replan was cancelled rather than burying it.
Force stays opt-in per explicit promote request: the hold-release sweep and the
webhook event release have no force parameter, so FN-7648 still holds for every
automatic surface.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>