feat(points): 实现积分流水列表功能

- 后端新增 GET /api/v1/points/ledger 接口
- 前端新增积分流水列表页面
- 积分中心添加「查看流水」入口
- 重命名 AccountDeleteScreen 为 AccountDataScreen
- 流水列表支持分页加载和空状态展示

backend/src/v1/points/router.py

@@ -1,18 +1,42 @@
 from __future__ import annotations
 
+from datetime import datetime
 from typing import Annotated
 
-from fastapi import APIRouter, Depends
+from fastapi import APIRouter, Depends, Query
 
 from core.auth.models import CurrentUser
+from core.http.errors import ApiProblemError, problem_payload
 from v1.points.dependencies import get_points_service
-from v1.points.schemas import PackagesResponse, PackageInfo, PointsBalanceResponse
+from v1.points.schemas import (
+    PackagesResponse,
+    PackageInfo,
+    PointsBalanceResponse,
+    LedgerListResponse,
+    LedgerItem,
+)
 from v1.points.service import PointsService
 from v1.users.dependencies import get_current_user
 
 router = APIRouter(prefix="/points", tags=["points"])
 
 
+def _parse_cursor(cursor: str | None) -> datetime | None:
+    if cursor is None:
+        return None
+    try:
+        return datetime.fromisoformat(cursor.replace("Z", "+00:00"))
+    except ValueError as exc:
+        raise ApiProblemError(
+            status_code=422,
+            detail=problem_payload(
+                code="POINTS_INVALID_CURSOR",
+                detail="Points ledger cursor must be an ISO 8601 datetime",
+                params={"cursor": cursor},
+            ),
+        ) from exc
+
+
 @router.get("/balance", response_model=PointsBalanceResponse)
 async def get_points_balance(
     service: Annotated[PointsService, Depends(get_points_service)],
@@ -55,3 +79,32 @@ async def get_available_packages(
             for pkg in result.packages
         ],
     )
+
+
+@router.get("/ledger", response_model=LedgerListResponse)
+async def get_points_ledger(
+    service: Annotated[PointsService, Depends(get_points_service)],
+    current_user: Annotated[CurrentUser, Depends(get_current_user)],
+    limit: Annotated[int, Query(ge=1, le=100)] = 20,
+    cursor: str | None = None,
+) -> LedgerListResponse:
+    items, next_cursor, has_more = await service.get_ledger_list(
+        user_id=current_user.id,
+        limit=limit,
+        cursor=_parse_cursor(cursor),
+    )
+    return LedgerListResponse(
+        items=[
+            LedgerItem(
+                id=item.id,
+                direction=item.direction,
+                amount=item.amount,
+                balanceAfter=item.balance_after,
+                changeType=item.change_type,
+                createdAt=item.created_at,
+            )
+            for item in items
+        ],
+        nextCursor=next_cursor,
+        hasMore=has_more,
+    )