This skill is a router. Execution runs inside the agentmaster-execute
custom agent, which dispatches implementer workers and never edits files in
this session.
Invoke the agentmaster-execute custom agent now, passing the plan path or
scope and any --headless flag verbatim. Do not implement the plan inline.
If the custom agent is not available, tell the user to run
python install.py install --target copilot from the agentmaster bundle.
Plan: $ARGUMENTS