Fix: ensure admin config is always stored with ID 1 to prevent persistence issues

backend/src/server.ts

@@ -237,21 +237,19 @@ app.delete('/api/stock/:id', async (req, res) => {
 app.post('/api/config', async (req, res) => {
   try {
     const { adminCode, finalDepositDate, cookDay, payIdInfo } = req.body;
-    const config = await prisma.config.findFirst();
     const data: any = {};
     if (adminCode !== undefined) data.adminCode = adminCode;
     if (finalDepositDate !== undefined) data.finalDepositDate = finalDepositDate;
     if (cookDay !== undefined) data.cookDay = cookDay;
     if (payIdInfo !== undefined) data.payIdInfo = payIdInfo;
 
-    if (config) {
-      await prisma.config.update({
-        where: { id: config.id },
-        data
+    // Use upsert to ensure we always use ID 1
+    await prisma.config.upsert({
+      where: { id: 1 },
+      update: data,
+      create: { ...data, id: 1 }
     });
-    } else {
-      await prisma.config.create({ data });
-    }
+    
     res.sendStatus(200);
   } catch (error) {
     console.error(error);
@@ -266,8 +264,14 @@ app.post('/api/reset', async (req, res) => {
     await prisma.stockItem.deleteMany();
     await prisma.config.deleteMany();
     
-    // Seed default admin code and limits
-    await prisma.config.create({ data: { adminCode: '1234', maxTotalWeight: 100.0, maxItemWeight: 50.0 } });
+    // Seed default admin code and limits with ID 1
+    await prisma.config.create({ 
+      data: { 
+        id: 1,
+        adminCode: '1234', 
+        payIdInfo: 'Your PayID Here'
+      } 
+    });
     
     // Seed some default stock items
     await prisma.stockItem.createMany({