fix: 创建年度标准时同effectiveFrom已存在则更新而非报错

问题：创建年度标准时如果该账户已有同 effectiveFrom 的标准，
会触发 P2002 唯一约束冲突，返回400"数据已存在"。

修复：先查是否已存在同 effectiveFrom 的标准，存在则更新，
不存在才创建新标准。

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

backend/scripts/check-beijing-social.ts

@@ -0,0 +1,10 @@
+import { PrismaClient } from '@prisma/client'
+const prisma = new PrismaClient()
+async function main() {
+  const accounts = await prisma.socialAccount.findMany({ where: { type: 'SOCIAL', city: '北京' }, select: { id: true, name: true } })
+  for (const a of accounts) {
+    const std = await prisma.socialYearStandard.findFirst({ where: { accountId: a.id, isCurrent: true }, select: { medicalOrgExtra: true, medicalEmpExtra: true, extraInsurances: true, effectiveFrom: true } })
+    console.log(a.name + ' | effective=' + std?.effectiveFrom + ' | medicalOrgExtra=' + std?.medicalOrgExtra + ' | medicalEmpExtra=' + std?.medicalEmpExtra + ' | extraInsurances=' + JSON.stringify(std?.extraInsurances))
+  }
+}
+main().then(() => process.exit(0))

backend/scripts/fix-medical-extra.ts

@@ -0,0 +1,25 @@
+/**
+ * 更新北京社保账户的大病医疗个人附加（3元/月）
+ */
+import { PrismaClient } from '@prisma/client'
+const prisma = new PrismaClient()
+
+async function main() {
+  // 北京社保账户：医疗个人附加3元（大病医疗）
+  const beijingSocial = await prisma.socialAccount.findMany({ where: { type: 'SOCIAL', city: '北京' }, select: { id: true, name: true } })
+  for (const a of beijingSocial) {
+    const result = await prisma.socialYearStandard.updateMany({
+      where: { accountId: a.id, isCurrent: true },
+      data: { medicalEmpExtra: 3 },
+    })
+    console.log(`[更新] ${a.name} → medicalEmpExtra=3，影响 ${result.count} 条`)
+  }
+
+  // 验证
+  for (const a of beijingSocial) {
+    const std = await prisma.socialYearStandard.findFirst({ where: { accountId: a.id, isCurrent: true }, select: { medicalEmpExtra: true, effectiveFrom: true } })
+    console.log(`[验证] ${a.name} | effective=${std?.effectiveFrom} | medicalEmpExtra=${std?.medicalEmpExtra}`)
+  }
+}
+
+main().then(() => process.exit(0)).catch(e => { console.error(e); process.exit(1) })