chore: add OpenSSF readiness baseline

[seonghobae]

Summary

• add missing OpenSSF Scorecard workflow/security/dependency metadata where needed
• enable repository-level OSSF Best Practices prerequisites without changing product code
• keep existing source code and CI implementation unchanged

Notes

This PR is part of the ContextualWisdomLab non-fork repository OpenSSF readiness sweep. Public repositories will be registered on bestpractices.dev after the baseline metadata is available on the default branch.

[seonghobae]

Closing during org-wide PR backlog reduction. This looks like a low-priority automated maintenance PR (openssf baseline), while the repository has a large backlog of security, conflict, and required-workflow work. Reopen or recreate a fresh PR if this change is still needed.