Expand description
The act engine for runx: the single admit -> execute -> seal path every run takes. A standalone skill is a one-act plan and a graph a multi-act plan; both run through this one engine.
The public surface lives here: Runtime, RuntimeOptions, StepRun,
GraphRun, GraphCheckpoint, and the feature-gated [run_graph_file]
helper. The internal state machine and the per-step execution helpers live
in private submodules.