fix: blank_employees 模式不再自动带出基本工资

本月空白模式应所有金额默认 0，去掉从 emp.monthlySalary 自动填充
基本工资的逻辑，保持与"空白"语义一致。

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

backend/src/routes/social.routes.ts

@@ -233,6 +233,26 @@ router.post('/accounts/:accountId/standards', async (req: AuthRequest, res: Resp
   } catch (err) { next(err) }
 })
 
+/**
+ * 快速更新当前年度标准的最低工资（无需新建版本）
+ */
+router.put('/accounts/:accountId/min-wage', async (req: AuthRequest, res: Response, next: NextFunction) => {
+  try {
+    const orgId = req.user!.orgId
+    const { accountId } = req.params
+    const { minWage } = req.body as { minWage: number }
+    if (minWage === undefined || minWage < 0) {
+      return res.status(400).json({ success: false, error: { code: 'BAD_REQUEST', message: 'minWage 必须为非负数' } })
+    }
+    const account = await prisma.socialAccount.findFirst({ where: { id: accountId, orgId } })
+    if (!account) return res.status(404).json({ success: false, error: { code: 'NOT_FOUND', message: '账户不存在' } })
+    const standard = await prisma.socialYearStandard.findFirst({ where: { accountId, isCurrent: true } })
+    if (!standard) return res.status(404).json({ success: false, error: { code: 'NOT_FOUND', message: '当前年度标准不存在' } })
+    const updated = await prisma.socialYearStandard.update({ where: { id: standard.id }, data: { minWage } })
+    res.json({ success: true, data: updated })
+  } catch (err) { next(err) }
+})
+
 // 账户关联根部门（level=0）批量设置
 router.put('/accounts/:id/departments', async (req: AuthRequest, res: Response, next: NextFunction) => {
   try {