fix: restore checkpoint peer ranges (#2713)

## Summary

Restores the published checkpoint peer ranges and local development
workspace references that were unintentionally narrowed by the
security-release dependency edits.

## Changes

- Restore the compatible public peer ranges for checkpoint integration
packages and `@langchain/langgraph-api`.
- Restore local checkpoint dev dependencies to `workspace:*`.
- Preserve the serializer security fix and avoid unnecessary
peer-dependent release cascades.