feat(ad): eCPM 单位统一为分 + 新增看广告金币审计接口 (#32)

- eCPM 口径修正:getEcpm 原值是分/千次,新增 parse_ecpm_fen;parse_ecpm_yuan
  改为 ÷100 转元,因子1 阈值按元判档(100/200/400),收益换算用元
- test-grant 用客户端按 ad_session_id 上报的真实 eCPM 发奖(取不到/≤0 兜底 200)
- 新增 GET /admin/api/ad-coin-audit 只读复算对账(router/repo/schema),复用发奖公式
- 同步更新 docs/api、docs/database 的分/元口径

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

---------

Co-authored-by: OuYingJun1024 <1034284404@qq.com>
Reviewed-on: #32
Co-authored-by: ouzhou <ouzhou@wonderable.ai>
Co-committed-by: ouzhou <ouzhou@wonderable.ai>

app/api/v1/ad.py

@@ -304,10 +304,18 @@ def test_grant(user: CurrentUser, db: DbSession, payload: TestGrantIn | None = N
             db.commit()
             db.refresh(rec)
     else:
+        # 优先用客户端按 ad_session_id 上报的真实 eCPM(走与正式发奖相同的公式);
+        # 取不到或 eCPM≤0(测试应用常返 0/假值)时兜底 200,保证本地联调仍能验出非零金币。
+        ad_session_id = payload.ad_session_id if payload is not None else None
+        ecpm_val = "200"
+        if ad_session_id:
+            ecpm_rec = crud_ecpm.find_by_session(db, user_id=user.id, ad_session_id=ad_session_id)
+            if ecpm_rec is not None and rewards.parse_ecpm_fen(ecpm_rec.ecpm_raw) > 0:
+                ecpm_val = ecpm_rec.ecpm_raw
         try:
             rec = crud_ad.grant_ad_reward(
-                db, user.id, trans_id, ecpm="200", reward_name="测试发奖",
-                raw="client debug test-grant ecpm=200",
+                db, user.id, trans_id, ecpm=ecpm_val, ad_session_id=ad_session_id,
+                reward_name="测试发奖", raw=f"client debug test-grant ecpm={ecpm_val}",
             )
         except crud_ad.UnknownUserError as e:
             raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="user not found") from e