Prevent oversell by conditioning stock updates and locking SKUs in primary-key order, and record the same concurrent-counter rule in the API spec and agent guide.
Co-authored-by: Cursor <cursoragent@cursor.com>
Persist the modular-monolith decision (ADR 0001 handler/service/repo,
ADR 0002 keep REST) with the companion tech spec and the api-architecture
OpenSpec capability. Replace the finished mock-migration tracker with
docs/TBD-marketing.md listing the backend-less marketing domains still on
fixtures (coupons, favorites, account stats, seckill, collective, integral,
reviews). README and AGENTS.md point at the new docs.
Chengdong ZhangandCursor