feat(ad): expose reward result by session

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

app/api/v1/ad.py

@@ -27,6 +27,7 @@ from app.repositories import ad_watch as crud_watch
 from app.repositories import app_config
 from app.repositories import signin as crud_signin
 from app.schemas.ad import (
+    AdRewardResultOut,
     AdRewardStatusOut,
     EcpmReportIn,
     EcpmReportOut,
@@ -242,6 +243,24 @@ def reward_status(user: CurrentUser, db: DbSession) -> AdRewardStatusOut:
     )
 
 
+@router.get(
+    "/reward-result/{ad_session_id}",
+    response_model=AdRewardResultOut,
+    summary="按广告会话查本次服务端权威发奖结果(弹窗展示实发金币用)",
+)
+def reward_result(ad_session_id: str, user: CurrentUser, db: DbSession) -> AdRewardResultOut:
+    """激励视频关闭后,客户端按本次 `ad_session_id` 查服务端到底发了多少金币,弹窗只展示这个权威数字。
+
+    只读、只查本人本会话的 reward_video 记录:没有记录=pending(S2S 尚未到账,客户端继续有限重试,
+    别把"未到账"当 0);granted 返回真实 coin;capped/closed_early/ecpm_missing 返回终态(coin=0,
+    不伪装成 granted)。不返回 eCPM / 回调原文 / 他人信息。
+    """
+    rec = crud_ad.find_reward_video_result(db, user.id, ad_session_id)
+    if rec is None:
+        return AdRewardResultOut(ad_session_id=ad_session_id, status="pending", coin=None)
+    return AdRewardResultOut(ad_session_id=ad_session_id, status=rec.status, coin=rec.coin)
+
+
 @router.post(
     "/watch-report",
     response_model=WatchReportOut,