备份：PWA配置前的完整版本

包含所有最新开发的功能和修复，作为PWA正确配置前的备份点。

backend/routes/inventory.js

@@ -81,6 +81,32 @@ router.get('/summary', async (req, res) => {
   }
 });
 
+router.post('/in', async (req, res) => {
+  try {
+    const { project_id, product_id, quantity, unit_price, total_amount, operator, remark } = req.body;
+    
+    const result = await db.query(`
+      INSERT INTO inventory_records 
+      (record_type, project_id, product_id, quantity, unit_price, total_amount, record_date, operator, remark)
+      VALUES ($1, $2, $3, $4, $5, $6, CURRENT_DATE, $7, $8)
+      RETURNING id
+    `, ['in', project_id || null, product_id, quantity, unit_price || null, total_amount || null, operator || '系统', remark || null]);
+    
+    res.json({
+      success: true,
+      message: '入库成功',
+      data: { id: result.rows[0]?.id }
+    });
+  } catch (error) {
+    console.error('入库失败:', error);
+    res.status(500).json({
+      success: false,
+      message: '入库失败',
+      error: process.env.NODE_ENV === 'development' ? error.message : '操作失败'
+    });
+  }
+});
+
 router.post('/out', async (req, res) => {
   try {
     const { project_id, product_id, quantity, unit_price, total_amount, operator, remark } = req.body;