feat(ECR-015): RedemptionCode 兑换码并 Closed

批次生成/作废、C 端兑码延长会员；admin-h5 /codes。
Loop continuous。Next：ECR-016 UserIntelligence。

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/CONTRACT_DIFF/ECR-015.yaml

@@ -0,0 +1,28 @@
+ecr: ECR-015
+capability: CommerceEntitlement
+bounded_context: Membership_Orders
+parent: WAVE0-FROZEN
+predecessor: ECR-014
+change:
+  type: additive
+breaking_change: false
+migration_required: true
+compatibility_notes: >
+  New redemption_batches / redemption_codes.
+  C-end POST /membership/redeem extends membership without payment.
+  Additive RBAC admin.membership.codes.read/write.
+
+entities:
+  - name: RedemptionBatch
+    before: null
+    after: { fields: [id, label, plan_code, quantity, created_by, created_at] }
+  - name: RedemptionCode
+    before: null
+    after: { fields: [id, batch_id, code, plan_code, status, redeemed_by, redeemed_at] }
+
+apis:
+  - { method: POST, path: /api/v1/admin/redemption-batches, change: added }
+  - { method: GET, path: /api/v1/admin/redemption-batches, change: added }
+  - { method: GET, path: /api/v1/admin/redemption-batches/{id}/codes, change: added }
+  - { method: POST, path: /api/v1/admin/redemption-codes/{id}/disable, change: added }
+  - { method: POST, path: /api/v1/membership/redeem, change: added }