feat(coin): 金币数值体系一期 — 签到加成 + 信息流广告结算

签到加成(boost):
- 新增 signin_boost_record 表(user+date 唯一)+ POST /api/v1/signin/boost
- signin 状态/结算逻辑调整

信息流广告结算:
- 新增 ad_feed_reward_record 表(client_event_id 幂等)+ POST /api/v1/ad/feed-reward
- ad_feed_reward 模型/repo、ad schema、按 ecpm/时长结算金币

金币数值:core/rewards.py 数值调整、config_schema/admin config 适配
迁移 coin_reward_phase1(down_revision pstat3growth);测试 + API/DB 文档同步

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_admin_config.py

@@ -69,14 +69,17 @@ def test_list_config(admin_client: TestClient, token: str) -> None:
     assert r.status_code == 200, r.text
     items = {i["key"]: i for i in r.json()}
     assert "signin_rewards" in items and "ad_daily_limit" in items
-    assert items["signin_rewards"]["value"] == [10, 20, 30, 50, 80, 120, 200]
+    assert items["signin_rewards"]["value"] == [
+        200, 120, 150, 180, 200, 250, 500,
+        200, 250, 300, 350, 400, 500, 3000,
+    ]
     assert items["signin_rewards"]["overridden"] is False
 
 
 def test_update_signin_takes_effect(admin_client: TestClient, token: str) -> None:
     r = admin_client.patch(
         "/admin/api/config/signin_rewards",
-        json={"value": [100, 200, 300, 400, 500, 600, 700]},
+        json={"value": [100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400]},
         headers=_auth(token),
     )
     assert r.status_code == 200, r.text
@@ -116,7 +119,7 @@ def test_update_ad_limit_takes_effect(admin_client: TestClient, token: str) -> N
 
 
 def test_config_validation(admin_client: TestClient, token: str) -> None:
-    # 签到档位长度≠7
+    # 签到档位长度≠14
     assert admin_client.patch(
         "/admin/api/config/signin_rewards", json={"value": [1, 2, 3]}, headers=_auth(token)
     ).status_code == 400