## ADDED Requirements

### Requirement: Merchant group-buying management
Shop users SHALL manage only their shop's group-buying activities in shop-admin, configuring an owned SKU, localized display content, minor-unit group price, required paid-member count, active window, and group lifetime. Shop-admin SHALL expose a group-buying navigation entry beside existing shop operations.

#### Scenario: publish activity
- **WHEN** a merchant publishes a valid group-buying activity
- **THEN** shoppers can discover it during its active window

#### Scenario: group buying appears in shop navigation
- **WHEN** an authenticated shop user opens shop-admin
- **THEN** a group-buying management entry is reachable without leaving the shop-scoped console