release: publish long-task continuity suite

[Golden-Promise]

Summary

• harden repo docs and package indexes for the long-task continuity suite release
• add PR CI for skills/*/tests, continuity eval unit tests, and evals/run_evals.py
• add bilingual release checklist and install smoke-test guidance for branch/main/tag flows

Validation

• for test_dir in skills/*/tests; do python3 -m unittest discover -s "$test_dir" -p '"'"'test_*.py'"'"' -v; done
• (cd skills/skill-governance && python3 scripts/manage_skill.py --validate-only)
• python3 -m unittest discover -s evals -p '"'"'test_*.py'"'"' -v
• python3 evals/run_evals.py

Maintainer Notes

• the suite adds skill-context-keeper, skill-phase-gate, skill-handoff-summary, and skill-task-continuity
• downstream users can install atomic packages directly or start with skill-task-continuity for composition/bootstrap guidance
• eval routing/workflow/artifact contracts are now treated as release-facing behavior