Cherry-picked from stale branch codex/wp-0012-scope-context (9709692).
main was still calling the old /repos/{slug}/scope path; repo-scoping now
serves GET /repos/{slug}/scope/context (web_api/app.py:1449). Includes the
resolver test and consistent workplan-doc updates. Test: 2 passed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
