TODO: Parameter set contract and optional CLI

Goal

Define and (where appropriate) implement the sibling JSON contract for parameter sets: numeric values fitted or chosen for a scaffold, referenced by content_hash (and/or model id + lockfile policy), not embedded as the sole truth in the INI [Parameters] section.

Why

• Aligns repositories with the scaffold vs parameter set split already stated in product docs and org contracts.
• Enables multiple value sets per scaffold (calibration, deployment, what-if) without duplicating equations.

Scope hints

• Contract first (schema, examples, ADR); model-parser might only validate or inspect parameter sets, or a separate small tool might own the file—keep scope guardrails in mind (repository root AGENTS.md).
• INI frontend might grow optional “declarations only” mode later; not required for the first parameter-set slice.

References

• docs/design/model-parser.md §4.
• docs/design/model-library-and-versioning.md §7.

Acceptance sketch

• Published JSON Schema (or org repo location) + example files.
• Clear story for how model-library (or customers) pins content_hash + set id.