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/main.py

@@ -0,0 +1,76 @@
+import asyncio
+from contextlib import asynccontextmanager
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from loguru import logger
+
+from app.config import settings
+from app.database import init_db
+from app.api import router
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    logger.info("启动推拉酸洗线二级系统...")
+    await init_db()
+    await _create_default_admin()
+
+    # 启动L1报文接收服务（UDP）
+    from app.services.message_parser import l1_server
+    import app.services.material_service  # noqa: 注册报文处理器
+    await l1_server.start()
+
+    logger.info("系统启动完成")
+    yield
+
+    l1_server.stop()
+    logger.info("系统已停止")
+
+
+async def _create_default_admin():
+    """首次启动时创建默认管理员"""
+    from app.database import AsyncSessionLocal
+    from sqlalchemy import select
+    from app.models.user import User
+    from app.services.auth_service import hash_password
+
+    async with AsyncSessionLocal() as db:
+        result = await db.execute(select(User).where(User.username == "admin"))
+        if not result.scalar_one_or_none():
+            admin = User(
+                username="admin",
+                full_name="系统管理员",
+                hashed_password=hash_password("admin123"),
+                role="admin",
+            )
+            db.add(admin)
+            await db.commit()
+            logger.info("默认管理员已创建: admin / admin123")
+
+
+app = FastAPI(
+    title="推拉酸洗线二级系统",
+    description="Pickling Line Level-2 MES System",
+    version="1.0.0",
+    lifespan=lifespan,
+)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=settings.CORS_ORIGINS,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(router, prefix="/api")
+
+
+@app.get("/health")
+async def health():
+    return {"status": "ok", "service": "pickling-mes"}
+
+
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run("app.main:app", host=settings.APP_HOST, port=settings.APP_PORT, reload=settings.DEBUG)