Turns the current session into the operator's SDLC proxy for parallel PRP workstreams in isolated worktrees. It owns the combined outcome, steers autonomous deliveries, holds human and merge gates, verifies proof, and sequences merges. Use when the user wants to "spawn N agents in separate worktrees", "run prp-issue on these issues in parallel", "orchestrate these features", "act as my orchestrator", "coordinate agents through the PRP pipeline", "ship these issues in parallel", or invokes /prp-orchestrate.