loop runs a worker agent and a reviewer agent iteratively using a graph.

parallel takes a list of Agent Pids and a Prompt. It prompts all agents concurrently using the graph engine.

Prompt agents concurrently with one overall deadline. Results retain the input PID order and contain {error, Reason} for failed branches.

sequential takes a list of Agent Pids and an Initial Prompt. It constructs a sequential graph of the agents and executes it.