Remove the internal design and execution plans from docs/plans and docs/superpowers so the public pull request contains only implementation and maintained user-facing documentation.
The four files were introduced only on this branch. No runtime code, generated output, README, CHANGELOG, or Skill documentation references them.
Verification:
- Confirmed origin/main does not contain the files.
- Confirmed no remaining repository references.
- Ran git diff --check before committing.