fix(orchestration): install base image juice-core from a local wheel, not the index

Release Python Package (twine upload) is gated on Build CI Base Image succeeding, but the base image build resolved orangeqs-juice-core from PyPI at the exact version being released -- a version that can never be published yet at that point. This deadlocked every release once the base-image pipeline landed, surfaced first on v26.30.0a1.

juice build now accepts --wheel-path to install a locally built wheel via [tool.uv.sources] instead of querying the index, and CI passes the wheel already produced by Package Python earlier in the pipeline.

Closes #396 (closed)

Co-Authored-By: Claude Sonnet 5 noreply@anthropic.com