feat(invite): 邀请奖励金账户(与金币隔离) + 比价发奖 + 奖励金提现

- 新增邀请奖励金独立账本: coin_account 加余额列 + invite_cash_transaction 流水表, 与金币现金物理隔离
- bind 改 v2: 绑定只发被邀请人新人金币; 邀请人改在好友首次成功比价时发 2 元奖励金(幂等只发一次)
- 提现链路按 source 分流: 扣款/退款/对账/分页各认账户, 两本账不串
- /invite/me 返回奖励金余额/累计提现/7天倒计时
- 新增 migration(建表加列) + 比价发奖与提现隔离测试

app/models/invite.py

@@ -10,7 +10,7 @@ from __future__ import annotations
 
 from datetime import datetime
 
-from sqlalchemy import DateTime, ForeignKey, Integer, String, func
+from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, String, false, func
 from sqlalchemy.orm import Mapped, mapped_column
 
 from app.db.base import Base
@@ -35,6 +35,20 @@ class InviteRelation(Base):
     inviter_coin: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
     invitee_coin: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
 
+    # ===== v2 比价发奖追踪(好友"下载+登录+比价一次"→ 给邀请人发邀请奖励金)=====
+    # 是否已因"好友完成比价"发过奖:好友比价多次只发一次(防重复发,与 invitee 唯一约束双保险)
+    compare_reward_granted: Mapped[bool] = mapped_column(
+        Boolean, nullable=False, default=False, server_default=false()
+    )
+    # 实发给邀请人的邀请奖励金(分);未发为 0
+    compare_reward_cents: Mapped[int] = mapped_column(
+        Integer, nullable=False, default=0, server_default="0"
+    )
+    # 发奖时间(未发为 None)
+    compare_rewarded_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True
+    )
+
     created_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), server_default=func.now(), index=True, nullable=False
     )