storage: add sqlite db for temp storage

[tcoratger]

🗒️ Description

For now to build a minimal client without external deps, sqlite with Python is enough, we can check later to use another db or build a custom one.

🔗 Related Issues or PRs

✅ Checklist

• Ran tox checks to avoid unnecessary CI fails:

  uvx tox

• Considered adding appropriate tests for the changes.
• Considered updating the online docs in the ./docs/ directory.