Supersede an in-progress task (terminate + spawn resume follow-up)

Marks the original task superseded (terminal) and creates a fresh taskType="resume" follow-up so a worker can pick up the work in a new provider session. Workflow-step tasks (those with workflowRunStepId) are carved out: the original is marked failed with reason superseded_workflow_task and no follow-up is created — the workflow engine's retry/failure policy applies.