fix(admin): 区分领券广告收益未填充与零收益 (#148)

## 修改内容
- 无 eCPM 填充记录时，领券数据接口返回 null
- 已填充但收益为 0 时保留 0.0
- 补充未填充与零收益的回归测试

## 验证
- 后端定向测试：7 passed
- Ruff 检查通过
- 线上近 30 天 740 条领券记录中，647 条无对应 eCPM 填充记录

---------

Co-authored-by: unknown <798648091@qq.com>
Reviewed-on: #148
Co-authored-by: linkeyu <linkeyu@wonderable.ai>
Co-committed-by: linkeyu <linkeyu@wonderable.ai>

app/admin/repositories/coupon_data.py

@@ -86,7 +86,12 @@ def _success_rates(rows: list) -> dict:
     }
 
 
-def _session_to_row(r, phone: str | None = None, nickname: str | None = None, ad_revenue_yuan: float = 0.0) -> dict:
+def _session_to_row(
+    r,
+    phone: str | None = None,
+    nickname: str | None = None,
+    ad_revenue_yuan: float | None = None,
+) -> dict:
     """CouponSession ORM → 明细行 dict(主表「领券数据」与「用户全部领券」抽屉共用)。"""
     return {
         "id": r.id,
@@ -252,7 +257,7 @@ def coupon_data_report(
     items = []
     for r in page:
         phone, nickname = user_map.get(r.user_id, (None, None)) if r.user_id is not None else (None, None)
-        items.append(_session_to_row(r, phone, nickname, ad_revenue_yuan=rev_map.get(r.trace_id, 0.0)))
+        items.append(_session_to_row(r, phone, nickname, ad_revenue_yuan=rev_map.get(r.trace_id)))
 
     return {
         "summary": summary,
@@ -276,7 +281,7 @@ def coupon_user_records(db: Session, *, user_id: int, limit: int = 100) -> dict:
     ).scalar_one()
     rev_map = crud_ecpm.revenue_yuan_by_trace(db, [r.trace_id for r in rows])
     return {
-        "items": [_session_to_row(r, ad_revenue_yuan=rev_map.get(r.trace_id, 0.0)) for r in rows],
+        "items": [_session_to_row(r, ad_revenue_yuan=rev_map.get(r.trace_id)) for r in rows],
         "total": int(total),
     }
 

app/admin/schemas/coupon_data.py

@@ -70,8 +70,9 @@ class CouponDataRow(BaseModel):
     started_at: datetime = Field(..., description="发起时刻(明细「时间」列)")
     claimed_count: int | None = None
     trace_url: str | None = Field(None, description="pricebot 公网 trace 链接(仅 completed 有);admin 渲染可点链接,无则显示可复制 trace_id")
-    ad_revenue_yuan: float = Field(
-        0.0, description="本次领券看的信息流广告预估收益(元);按 trace_id 聚合 ad_ecpm_record"
+    ad_revenue_yuan: float | None = Field(
+        None,
+        description="本次领券看的信息流广告预估收益(元);按 trace_id 聚合 ad_ecpm_record;无填充记录为 null",
     )