OpalTaskRuntime Class

Detailed Description

Accepts TaskPlan submissions and runs steps sequentially on a background thread. Emits signals for per-step results, progress updates, and plan completion.

Without a resource manager it rejects a submission while another plan is running; with one, plans whose resource scopes do not collide run at once, each with its own cancel, stop and skip (kiln §KN-P-OPAL). Not a singleton — multiple instances can exist (e.g., in tests).