Compatibility Commitments

Compatibility commitments are expensive promises. They should be visible enough that nobody expands them by accident.

Package Surface

• treat foundation types as cross-package contracts, not local implementation detail
• version movement must be explicit and reviewable
• shared meanings should change slower than downstream workflow code

First Proof Check

• src/bijux_proteomics_foundation/ids.py and schema.py
• src/bijux_proteomics_foundation/serialization.py and migrations.py
• packages/bijux-proteomics-foundation/tests