Remove the superseded move plan and spec under docs/superpowers (contains pip install) #272

docs/superpowers/plans/2026-10-22-python-bindings-move.md and docs/superpowers/specs/2026-10-22-python-bindings-move-design.md are the internal plan and design of the move into this repository. The move is done, the plan is superseded, and neither file is part of the published docs (the Antora component builds only docs/modules/ROOT). The plan still contains pip install (line 265), against the rule that user-facing text says uv add, and both files name the old package, which is why scripts/check_no_embedded_name.py carries an allowlist entry for docs/superpowers/*.

Proposal: delete both files, remove the allowlist entry and its docstring bullet in scripts/check_no_embedded_name.py, and fix the comment in tests/conftest.py that mentions docs/superpowers. The history stays in git, and the live migration notes are kept outside the repository. This was item M2 of the 2026-11-04 docs audit (#267).