feat(coupon): 今日跑完整轮领券后端记录 + 查询(首页置灰源) (#34)

新增 coupon_daily_completion 表:按 (device_id, 自然日) 记"今天是否已跑完
整轮领券(到 done 帧)"。客户端据此把首页「去领取」卡置灰、不可点。

口径(用户决策 A 方案):到 done 即算,不管单券成败 —— 失败/跳过常是无障碍/
环境问题,重复点也补不回来。判断维度 device_id,与 engagement/claim 一致。

- model CouponDailyCompletion(uq device+complete_date,仿 CouponPromptEngagement)
- repo has_completed_today / mark_completed_today(幂等 upsert + IntegrityError 兜底)
- schema CouponCompletedTodayOut(completed: bool)
- coupon_step 透传链路在 action.command=="done" 那帧 best-effort 写完成记录
  (pricebot 只在整轮全跑完才保留 command=="done",故无需再判 continue)
- GET /api/v1/coupon/completed-today?device_id= 供首页查询
- alembic 迁移 coupon_daily_completion(down_revision=0cf18d590b1d 当前 head)

合并后需 alembic upgrade head,否则 /completed-today 500。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: no_gen_mu <liujianhishen@gmail.com>
Reviewed-on: #34
Co-authored-by: liujiahui <liujiahui@wonderable.ai>
Co-committed-by: liujiahui <liujiahui@wonderable.ai>

app/models/__init__.py

@@ -9,6 +9,7 @@ from app.models.comparison import ComparisonRecord  # noqa: F401
 from app.models.comparison_milestone import ComparisonMilestoneClaim  # noqa: F401
 from app.models.coupon_state import (  # noqa: F401
     CouponClaimRecord,
+    CouponDailyCompletion,
     CouponPromptEngagement,
 )
 from app.models.feedback import Feedback  # noqa: F401

app/models/coupon_state.py

@@ -93,6 +93,49 @@ class CouponClaimRecord(Base):
         )
 
 
+class CouponDailyCompletion(Base):
+    """按 (device, 自然日) 记"今天是否已跑完整轮领券(到 done 帧)"——首页置灰源。
+
+    与 engagement 区别:engagement = 用户表达过意向(点了一键领取/拒绝即记,不管跑没跑完);
+    completion = 这一轮真跑到了 done(整套流程走完)。首页「去领取」卡据此置灰:跑完了
+    今天就不能再领。判断口径(用户决策 2026-06-10 A 方案):**到 done 即算**,不管单券
+    成败(失败/跳过常是无障碍/环境问题,重复点也补不回来)。判断维度 device_id,与
+    engagement/claim 一致。
+    """
+
+    __tablename__ = "coupon_daily_completion"
+    __table_args__ = (
+        # 一台设备一天一条:今天跑完过就置灰。
+        UniqueConstraint(
+            "device_id", "complete_date",
+            name="uq_coupon_completion_device_date",
+        ),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    device_id: Mapped[str] = mapped_column(String(64), nullable=False)
+    user_id: Mapped[int | None] = mapped_column(Integer, index=True, nullable=True)
+    # Asia/Shanghai 自然日。
+    complete_date: Mapped[date] = mapped_column(Date, nullable=False)
+    # 哪次任务跑到 done,回指 pricebot work_logs / 排查。
+    trace_id: Mapped[str | None] = mapped_column(String(64), index=True, nullable=True)
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(),
+        nullable=False,
+    )
+
+    def __repr__(self) -> str:  # pragma: no cover
+        return (
+            f"<CouponDailyCompletion device={self.device_id} "
+            f"date={self.complete_date}>"
+        )
+
+
 class CouponPromptEngagement(Base):
     """按 (device, 自然日) 记"今天是否对领券引导窗表达过意向"——弹窗频控源。"""