Advance the local research workflow

[foxsplendid]

Summary

• advance the local-first research control loop with migration, resume, status, and acceptance tooling
• pin and validate the public suite component candidates through contract-compatible workflows
• add credential-free, public-pull, and offline Steward-to-Lectern synthetic golden paths
• harden clean Windows installation and cross-platform rollback acceptance checks

Verification

• local: 280 tests passed; 7 Windows symlink tests skipped when the current account lacks symlink privilege
• GitHub Actions: all Ubuntu/Windows Python 3.11/3.12 unit jobs and the Windows end-to-end job passed
• CI evidence: https://github.com/scriptorium-suite/scriptorium/actions/runs/30079916819

Privacy and release boundary

• public repositories and synthetic fixtures only
• no private research data, credentials, or personal email addresses are included
• this PR is a review candidate only; it does not authorize merging, tagging, or releasing