PRDs: Pricing

Sorted by suggested reading order, top to bottom. Status syncs from Plane on every build - the all-module view lives in the PRD Register.

#	ID	Name	Description	Surface	Status
1	PRD-FARE-001	Fare & Tax Pricing Engine	Product requirements for the Fare & Tax Pricing Engine priority-tier fare selection per variant, priority-ordered tax computation, and an immutable pricing snapshot the sale flow consumes at checkout	BackendClient	Ready to dev
2	PRD-SIM-001	Pricing simulation & order pricing preview	Product requirements for the stateless pricing simulation engine it returns an immutable, auditable pricing snapshot (order + per-line, with a per-party ledger), plus the read-only order-pricing preview the sale flow consumes before checkout without persisting an order	Backend	Ready to dev
3	PRD-PROMO-001	Promotions, methods & segment rules	Product requirements for configuring promotion campaigns a promotion carries exactly one method (fixed or percentage, targeting items, the order, or shipping, with an allocation strategy), a standard or buy-get scheme, and three rule sets (eligibility, source, target) that segment who qualifies, what must be bought, and what gets discounted all created and edited as one atomic aggregate	Client	Ready to dev