批次5：inventory服务下沉收口 + Pydantic v2 / datetime弃用清零

- inventory业务层下沉（薄路由+service orchestration模式）：
  - customer/supplier/warehouse -> master_data_service
  - material_routes（价格历史/趋势/供应商关联）-> material_service
  - product_routes（CRUD/BOM/from-task跨模块桥接）-> product_service
  - dashboard_routes（首页统计/低库存预警）-> dashboard_service
- inventory侧新增service回归覆盖（dashboard 2 / master_data 10 /
  material 10 / product 14），含跨模块桥接测试种子
- Pydantic v2弃用清零：全仓14处 class Config 全部迁移到
  model_config = ConfigDict(from_attributes=True)（含 shared auth）
- datetime.utcnow() 弃用清零：auth_service 3处统一改 datetime.now(timezone.utc)
- 同步文档：STATUS / ROADMAP / TECH_DEBT（D12清偿）/ AGENTS 代码地图

测试基线：126 passed, 4 skipped（无deprecation warning）

Co-Authored-By: Claude Code <noreply@anthropic.com>

src/inventory/api/dashboard_routes.py

@@ -11,12 +11,11 @@
 """
 from fastapi import APIRouter, Depends
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy import select, func
 
 from shared.database.database import get_db_session
 from shared.services.auth_service import get_current_active_user
 from shared.models.identity import User
-from inventory.models import Product, Supplier, Customer, Warehouse, Inventory, PurchaseOrder, SalesOrder
+from ..services.dashboard_service import dashboard_service
 
 router = APIRouter(prefix="/dashboard", tags=["仪表盘"])
 
@@ -26,55 +25,4 @@ async def get_dashboard(
     db_session: AsyncSession = Depends(get_db_session),
     current_user: User = Depends(get_current_active_user)
 ):
-    material_count = await db_session.scalar(
-        select(func.count(Product.id)).where(Product.is_active == True, Product.item_type == "material")
-    ) or 0
-    finished_product_count = await db_session.scalar(
-        select(func.count(Product.id)).where(Product.is_active == True, Product.item_type == "finished")
-    ) or 0
-    supplier_count = await db_session.scalar(select(func.count(Supplier.id)).where(Supplier.is_active == True))
-    customer_count = await db_session.scalar(select(func.count(Customer.id)).where(Customer.is_active == True))
-    warehouse_count = await db_session.scalar(select(func.count(Warehouse.id)).where(Warehouse.is_active == True))
-    
-    total_stock = await db_session.scalar(
-        select(func.sum(Inventory.quantity))
-        .join(Product, Inventory.product_id == Product.id)
-        .where(Product.item_type == "material")
-    ) or 0
-    total_value = await db_session.scalar(
-        select(func.sum(Inventory.quantity * Product.cost_price))
-        .join(Product, Inventory.product_id == Product.id)
-        .where(Product.item_type == "material")
-    ) or 0
-    
-    pending_purchase = await db_session.scalar(
-        select(func.count(PurchaseOrder.id)).where(PurchaseOrder.status == "pending")
-    )
-    pending_sales = await db_session.scalar(
-        select(func.count(SalesOrder.id)).where(SalesOrder.status == "pending")
-    )
-    
-    low_stock_products = await db_session.execute(
-        select(Product, Inventory)
-        .join(Inventory, Product.id == Inventory.product_id)
-        .where(Product.item_type == "material")
-        .where(Inventory.quantity <= Product.min_stock)
-        .limit(10)
-    )
-    low_stock = [
-        {"id": p.id, "name": p.name, "sku": p.sku, "quantity": i.quantity, "min_stock": p.min_stock}
-        for p, i in low_stock_products.all()
-    ]
-    
-    return {
-        "finished_product_count": finished_product_count,
-        "material_count": material_count,
-        "supplier_count": supplier_count,
-        "customer_count": customer_count,
-        "warehouse_count": warehouse_count,
-        "total_stock": total_stock,
-        "total_value": round(total_value, 2),
-        "pending_purchase": pending_purchase,
-        "pending_sales": pending_sales,
-        "low_stock_products": low_stock
-    }
+    return await dashboard_service.get_dashboard(db_session)