ci: version-sync guard (package.json / pyproject / __init__) — Closes #102

[wesleysimplicio]

Summary

Closes #102. Adds a Python version-sync guard and wires it into CI so a partial SemVer bump cannot merge or publish.

Changes

• scripts/check-version-sync.py (preferred) — compares package.json, pyproject.toml, and simplicio_mapper/__init__.py; exit 1 on mismatch
• .github/workflows/version-sync.yml — runs on PR/push to main
• publish-pypi.yml — same guard before tag/version verification
• __init__.py — importlib.metadata.version("simplicio-mapper") with static fallback string (still the SoT for the file guard)
• Docs — .specs/workflow/RELEASE.md triple-file bump checklist; CONTRIBUTING/AGENTS/CLAUDE/scripts README
• Tests — tests/python/test_check_version_sync.py (align + deliberate mismatch)

Legacy scripts/check-version-sync.js kept as a twin with the same contract.

Verification (MEASURED)

python scripts/check-version-sync.py          # exit 0 — version 0.26.18 aligned
python -m pytest tests/python/test_check_version_sync.py -q  # 6 passed
# deliberate mismatch fixture → exit 1 with per-file report

Acceptance criteria

• Deliberate mismatch fails the checker (exit 1)
• Check runs automatically on PR (version-sync.yml)
• Static __version__ stays aligned with both manifests (importlib optional override at runtime)