feat(admin): 上报更低价人工审核（通过发1000金币/拒绝填理由） (#33)

运营后台审核用户上报的「某平台比我们算的最低价更便宜」+截图。

- routers/price_report.py：列表 + /summary、approve|reject（require operator）
- repositories：list_price_reports + price_report_summary（queries）、review_price_report（mutations）
- core/rewards.py：PRICE_REPORT_REWARD_COINS=1000（通过即发，grant_coins 由 router 同事务调）
- admin/main.py：注册 price_report_router

跨端配套：前端 admin-web feat/price-report-review；端上金币刷新 android feat/price-report-review。

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: xianze <ze@192.168.0.128>
Reviewed-on: #33
Co-authored-by: zhangxianze <zhangxianze@wonderable.ai>
Co-committed-by: zhangxianze <zhangxianze@wonderable.ai>

app/admin/schemas/price_report.py

@@ -0,0 +1,46 @@
+"""admin 上报更低价审核 schemas。"""
+from __future__ import annotations
+
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict, Field
+
+
+class PriceReportOut(BaseModel):
+    """admin 列表项:price_report 全字段(审核要看的快照 + 截图 + 状态 + 奖励)。"""
+
+    model_config = ConfigDict(from_attributes=True)
+
+    id: int
+    user_id: int
+    comparison_record_id: int | None = None
+    # 选中比价记录的快照
+    store_name: str | None = None
+    dish_summary: str | None = None
+    original_platform_id: str | None = None
+    original_platform_name: str | None = None
+    original_price_cents: int | None = None
+    # 用户上报的更低价
+    reported_platform_id: str
+    reported_platform_name: str
+    reported_price_cents: int
+    images: list[str] = []
+    # 审核
+    status: str
+    reject_reason: str | None = None
+    reward_coins: int | None = None
+    reviewed_at: datetime | None = None
+    created_at: datetime
+
+
+class PriceReportRejectRequest(BaseModel):
+    reason: str = Field(min_length=1, max_length=256, description="拒绝理由,用户端记录页会看到")
+
+
+class PriceReportSummary(BaseModel):
+    """审核台顶部各状态计数。"""
+
+    pending: int
+    approved: int
+    rejected: int
+    total: int