feat(admin): 首页门面数字保底/护栏 + 轮播种子真实化与批量 + 比价记录索引

- ops_stat: 真实值 offset→保底(max);初始基数过只增不减护栏
- ops_marquee: 脱敏名手机尾号+中文昵称混合;金额长尾;时间随机抖动;真实+种子不足兜底补满;真实记录查询 ~30s 缓存
- comparison_record: 复合索引 (status, created_at) + 迁移(PG CONCURRENTLY);修复 alembic 多 head(merge 改挂 onboarding_completion)
- 轮播种子批量删除/启用接口 + ids 上限;docs 同步
- 附带并行会话 WIP:admin users / wallet

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

app/admin/routers/users.py

@@ -12,6 +12,7 @@ from app.admin.schemas.common import CursorPage, OkResponse
 from app.admin.schemas.user import (
     AdminUserListItem,
     AdminUserOverview,
+    GrantCashRequest,
     GrantCoinsRequest,
     SetDebugTraceRequest,
     SetUserStatusRequest,
@@ -132,3 +133,42 @@ def grant_user_coins(
     )
     db.commit()
     return OkResponse()
+
+
+@router.post("/{user_id}/cash", response_model=OkResponse, summary="手动增减现金(带审计)")
+def grant_user_cash(
+    user_id: int,
+    body: GrantCashRequest,
+    request: Request,
+    admin: Annotated[AdminUser, Depends(require_role("finance"))],
+    db: AdminDb,
+) -> OkResponse:
+    """给指定用户增/减现金(分)。正=发放、负=扣减;主要用于让无现金用户直接测试提现。"""
+    if body.amount_cents == 0:
+        raise HTTPException(status_code=400, detail="amount_cents 不能为 0")
+    user = user_repo.get_user_by_id(db, user_id)
+    if user is None:
+        raise HTTPException(status_code=404, detail="用户不存在")
+    # 负数扣减时不允许扣成负余额(运营误操作保护)
+    if body.amount_cents < 0:
+        acc_now = wallet_repo.get_or_create_account(db, user_id, commit=False)
+        if acc_now.cash_balance_cents + body.amount_cents < 0:
+            raise HTTPException(
+                status_code=400, detail=f"扣减后现金为负(当前余额 {acc_now.cash_balance_cents} 分)"
+            )
+    biz_type = "admin_grant" if body.amount_cents > 0 else "admin_deduct"
+    # grant_cash 只 flush 不 commit;审计同 commit=False;最后一起 commit → 原子(改钱+留痕)
+    acc, _ = wallet_repo.grant_cash(
+        db, user_id, body.amount_cents, biz_type=biz_type, remark=f"admin:{body.reason}"[:128],
+    )
+    write_audit(
+        db, admin, action="user.cash.grant", target_type="user", target_id=user_id,
+        detail={
+            "amount_cents": body.amount_cents,
+            "balance_after_cents": acc.cash_balance_cents,
+            "reason": body.reason,
+        },
+        ip=get_client_ip(request), commit=False,
+    )
+    db.commit()
+    return OkResponse()