Get Quant Regimes

The 6-regime taxonomy reference (any valid key).

Stable vocabulary for all quant endpoints: id, label, display name, description and the suggested algo-basket stance per regime. Raw HMM states map many-to-one onto these labels; the labels are the API contract. catalog_version is the versioned guarantee behind that: unchanged means every id still maps to the same label you can see here — safe to pin regime.id directly rather than re-resolving label each call.