Parse source files and emit the execution plan as JSON

Usage: barca plan [OPTIONS] <FILES>...

Arguments:
  <FILES>...  Python source files containing @asset definitions

Options:
      --env <ENV>  Environment name (accepted for symmetry; planning uses no state)
  -h, --help       Print help

Examples:
  barca plan pipeline.py              # phases and steps that would run; nothing executes
  barca plan pipeline.py other.py     # several files form one DAG

Output: always pretty-printed JSON {total_steps, phases: [{reason, streams: [{stream_id, steps}]}]}.
Planning is static analysis: it never imports your code.
More: barca docs agents
