Description

Ensure all outputs include full provenance for reproducibility.

Tasks

• Implement data hash calculation (SHA256)
• Add version tagging to all responses
• Store provenance metadata in database
• Include Polygon API version info
• Add timestamp generation
• Create provenance audit endpoint

Documentation

• See docs/02-api-specification.md for provenance format
• See docs/03-system-architecture.md Section 13 for data governance

Acceptance Criteria

• All responses include data_hash and version
• Same inputs produce identical hashes
• Provenance is fully auditable