Get the active loyalty program config
Returns the loyalty plan the earn/burn maths currently applies: accrualPointsPerCent (points granted per cent spent — 0.01 means 1 point per euro), redemptionCentsPerPoint (the discount one point buys), the tier ladder ordered by minLifetimePoints, and the optional points-expiry policy. Read this before quoting any points value to a customer, and before calling updateLoyaltyConfig — that verb replaces the WHOLE document. Always 200: before anything has been saved it returns the seeded default plan, never a 404.
Authorizations
Authorization: Bearer <token>. Accepts EITHER a Keycloak access token (scopes-in-token) OR an opaque POS session token; both resolve to the same pos.* scope vocabulary the route guards enforce.
Response
The active program rules (the seeded default until one is saved).

