feat: 移除PDI和订单号字段，新增设备巡检模块

- 从物料跟踪页面移除订单号列和表单字段
- 从导航菜单移除PDI管理，添加设备巡检
- 新增InspectionLocation和InspectionRecord后端模型和API
- 新增设备巡检前端页面（左侧点位列表，右侧设备和历史记录）

backend/app/api/downtime.py

@@ -0,0 +1,108 @@
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select, func, desc
+from typing import Optional
+from datetime import datetime
+
+from app.database import get_db
+from app.models.downtime import DowntimeRecord, DowntimeCategory
+from app.schemas.downtime import (
+    DowntimeCreate, DowntimeUpdate, DowntimeOut,
+    CategoryCreate, CategoryOut
+)
+from app.schemas.common import Response, PageResponse
+from app.services.auth_service import get_current_user
+
+router = APIRouter()
+
+
+def _parse_dt(s):
+    if not s:
+        return None
+    try:
+        return datetime.fromisoformat(s.replace('Z', ''))
+    except Exception:
+        return None
+
+
+@router.get("/categories", response_model=Response[list[CategoryOut]])
+async def list_categories(db: AsyncSession = Depends(get_db), _ = Depends(get_current_user)):
+    result = await db.execute(select(DowntimeCategory).where(DowntimeCategory.is_active == 1))
+    return Response.ok([CategoryOut.model_validate(c) for c in result.scalars()])
+
+
+@router.post("/categories", response_model=Response[CategoryOut])
+async def create_category(
+    body: CategoryCreate,
+    db: AsyncSession = Depends(get_db),
+    _ = Depends(get_current_user),
+):
+    cat = DowntimeCategory(**body.model_dump())
+    db.add(cat)
+    await db.flush()
+    return Response.ok(CategoryOut.model_validate(cat))
+
+
+@router.get("/", response_model=Response[PageResponse[DowntimeOut]])
+async def list_downtime(
+    page: int = 1,
+    page_size: int = 20,
+    category_code: Optional[str] = None,
+    shift: Optional[str] = None,
+    start_date: Optional[str] = Query(None),
+    end_date: Optional[str] = Query(None),
+    is_planned: Optional[int] = None,
+    db: AsyncSession = Depends(get_db),
+    _ = Depends(get_current_user),
+):
+    query = select(DowntimeRecord).order_by(desc(DowntimeRecord.start_time))
+    if category_code:
+        query = query.where(DowntimeRecord.category_code == category_code)
+    if shift:
+        query = query.where(DowntimeRecord.shift == shift)
+    _sd = _parse_dt(start_date)
+    if _sd:
+        query = query.where(DowntimeRecord.start_time >= _sd)
+    _ed = _parse_dt(end_date)
+    if _ed:
+        query = query.where(DowntimeRecord.start_time <= _ed)
+    if is_planned is not None:
+        query = query.where(DowntimeRecord.is_planned == is_planned)
+
+    total = (await db.execute(select(func.count()).select_from(query.subquery()))).scalar()
+    result = await db.execute(query.offset((page - 1) * page_size).limit(page_size))
+    items = [DowntimeOut.model_validate(r) for r in result.scalars()]
+    return Response.ok(PageResponse(total=total, page=page, page_size=page_size, items=items))
+
+
+@router.post("/", response_model=Response[DowntimeOut])
+async def create_downtime(
+    body: DowntimeCreate,
+    db: AsyncSession = Depends(get_db),
+    _ = Depends(get_current_user),
+):
+    record = DowntimeRecord(**body.model_dump())
+    db.add(record)
+    await db.flush()
+    return Response.ok(DowntimeOut.model_validate(record))
+
+
+@router.put("/{record_id}", response_model=Response[DowntimeOut])
+async def update_downtime(
+    record_id: int,
+    body: DowntimeUpdate,
+    db: AsyncSession = Depends(get_db),
+    _ = Depends(get_current_user),
+):
+    result = await db.execute(select(DowntimeRecord).where(DowntimeRecord.id == record_id))
+    record = result.scalar_one_or_none()
+    if not record:
+        raise HTTPException(status_code=404, detail="停机记录不存在")
+    update_data = body.model_dump(exclude_none=True)
+    for k, v in update_data.items():
+        setattr(record, k, v)
+    if record.end_time and record.start_time:
+        delta = (record.end_time - record.start_time).total_seconds() / 60
+        record.duration = round(delta, 2)
+    await db.flush()
+    return Response.ok(DowntimeOut.model_validate(record))