Relax ScaffoldHub dependency constraint to >=0.1.6

## Summary

Update the ROCK MCP extra to depend on `scaffoldhub>=0.1.6` instead of pinning exactly `0.1.6`.

## Scope

- Relax the dependency constraint in `pyproject.toml`.
- Regenerate/update `uv.lock` consistently.
- Update the packaging assertion and relevant dependency documentation.

## Rationale

Allow compatible ScaffoldHub releases newer than 0.1.6 while retaining 0.1.6 as the minimum supported version.

Start in pyproject.toml and inspect the ROCK MCP extra's ScaffoldHub dependency constraint. Regenerate or update uv.lock consistently, then locate the packaging assertion and relevant dependency documentation mentioned in the issue. Done means the minimum remains 0.1.6, newer compatible releases are allowed, and the lockfile, assertion, and documentation agree.

Written by the indexing model from the issue text.