Validate PolicyEngine-US and policyengine-us-data version compatibility #107

Context

The original strategy review raised dependency-stack risks:

• The local TOB repo venv could use an older policyengine-us than the intended 6830-port/current stack.
• policyengine-us-data projected datasets came from a feature branch and need validation against the active policyengine-us version.
• Batch requirements did not pin policyengine-us, risking different local/batch/Modal versions.

Work

• Define the intended model stack for the CRFB rerun: policyengine-us, policyengine-core, policyengine-us-data, branch/commit, and dataset snapshot.
• Validate H5 compatibility and variable availability across the intended 75-year scoring range.
• Pin or record versions for batch, Modal, local scripts, and saved-H5 scoring.
• Add a smoke test proving local and Modal use the same dependency stack.

Acceptance Criteria

• Every production result artifact has dependency-stack metadata.
• Local, batch, Modal, and saved-H5 paths cannot silently use different PE-US versions.
• Any remaining custom branch dependency is documented with merge/pin status.

Related: #84, #86, #98, #99.