release: prepare beta prereleases

[cesarenaldi]

Summary

• set the package version and release-please manifest to 0.1.0b1
• enable release-please beta prerelease mode for future beta bumps
• update uv.lock to match the beta version

Verification

• uv run ruff check .
• uv run ruff format --check .
• uv run pyright
• uv run pytest -m "not integration"
• uv build

---

Note

Low Risk
Low risk: release metadata-only changes that affect versioning/release automation but not runtime behavior.

Overview
Prepares the Python package for beta prereleases by bumping the project/manifest version from 0.1.0 to 0.1.0b1 and updating uv.lock accordingly.

Updates release-please-config.json to enable beta prerelease mode (prerelease: true, prerelease-type: beta) for future automated prerelease bumps.

^{Reviewed by Cursor Bugbot for commit e929919. Bugbot is set up for automated code reviews on this repo. Configure here.}