Continues the Phase 1 contract doc with the same wire-contract-only style.
All three build on Sprint 0.1's answered decisions - no further business
input needed to start implementation once backend ownership is confirmed:
- Phase 2: canonical Order/OrderLine/Fulfillment/OrderEvent per the unified
multi-seller decision (one Order, per-seller Fulfillment groups), event
bus, Notification Center contract.
- Phase 3: Product/Offer split, InventoryRecord, publish-time executability
validation (the mechanism behind "no branch may distinguish an inspector
from a normal buyer").
- Phase 4: generic config-driven connector framework per the "no fixed
marketplace list" decision - onboarding a new partner is configuration
against a fixed pipeline, not a bespoke integration.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>