fix(refs): resolve logical group statuses

[bwl21]

Merge order and gate

This is step 2 of the intended issue order: #143 → #157 → #164.

• Wait for: feat: support read-only external references across ct projects #143 to be merged into main.
• Current state: draft; the branch already contains feat: support read-only external references across ct projects #143 as its prerequisite, so merging it early would land both issues together.
• After feat: support read-only external references across ct projects #143 merges: rebase/update this branch onto the new main, rerun all checks, verify that the remaining diff contains only bug(refs): resolve group statuses from /person/masterdata instead of treating #67 as permanent #157, and mark this PR ready for review.
• After bug(refs): resolve group statuses from /person/masterdata instead of treating #67 as permanent #157 merges: rebase/update feat(server): versioned REST API for ChurchTools Extension clients #164 onto the new main, rerun its checks, and then mark the REST PR ready.

The source branches live in the bwl21/ct-cli fork. GitHub does not support cross-fork stacked PR bases, so this PR technically targets main; the draft state is the explicit merge-order gate.

Summary

• load the group-status catalog from /person/masterdata and resolve technical status names to host-local IDs
• reverse-resolve known groupStatusId values during adoption while preserving unknown numeric IDs with an actionable portability warning
• keep existing numeric input backward compatible and distinguish group statuses from membership and person statuses in documentation and code comments
• cover hosts that assign different numeric IDs to the same technical status name

Testing

• npm run test — 1,083 passed, 5 skipped
• npm run typecheck
• npm run lint
• npm run format:check
• npm run build
• node .github/scripts/docs-staleness.mjs
• mkdocs build -f docs/handbuch/mkdocs.yml --strict

Closes #157