fix: 风险重复问题

1. runRiskDetection开头清理重复PENDING记录(同employeeId:type只保留最新)
2. onboardingRisks过滤掉已被contractRisks覆盖的员工，避免同一员工出现'未签合同'+'入职手续未完成'两条重复待办

backend/src/services/risk.service.ts

@@ -508,6 +508,29 @@ export async function detectRetirementRisks(orgId: string) {
 }
 
 export async function runRiskDetection(orgId: string) {
+  // 清理重复 PENDING 风险：同一 employeeId:type 只保留最新一条 PENDING
+  const pendingRisks = await prisma.riskItem.findMany({
+    where: { orgId, status: 'PENDING', employeeId: { not: null } },
+    select: { id: true, employeeId: true, type: true, createdAt: true },
+    orderBy: { createdAt: 'desc' },
+  })
+  const seenKeys = new Set<string>()
+  const duplicateIds: string[] = []
+  for (const r of pendingRisks) {
+    const key = `${r.employeeId}:${r.type}`
+    if (seenKeys.has(key)) {
+      duplicateIds.push(r.id)
+    } else {
+      seenKeys.add(key)
+    }
+  }
+  if (duplicateIds.length > 0) {
+    await prisma.riskItem.updateMany({
+      where: { id: { in: duplicateIds } },
+      data: { status: 'RESOLVED', resolvedAt: new Date() },
+    })
+  }
+
   // 非月度风险去重：检查所有状态（含 RESOLVED/IGNORED），避免已处理的风险被重新创建
   // 按 employeeId:type 归并，不依赖 actionUrl（actionUrl 可能因天数变化而不同）
   const existingRisks = await prisma.riskItem.findMany({
@@ -538,8 +561,12 @@ export async function runRiskDetection(orgId: string) {
   const specialStatusRisks = await detectSpecialStatusRisks(orgId)
   const retirementRisks = await detectRetirementRisks(orgId)
 
+  // 去重：contractRisks 已覆盖"未签合同"，onboardingRisks 中相同员工不再重复生成
+  const contractEmployeeIds = new Set(contractRisks.map(r => r.employeeId))
+  const filteredOnboardingRisks = onboardingRisks.filter(r => !contractEmployeeIds.has(r.employeeId))
+
   // 获取所有相关员工数据用于风险量化
-  const allEmployeeIds = [...contractRisks, ...terminationRisks, ...onboardingRisks, ...specialStatusRisks, ...retirementRisks]
+  const allEmployeeIds = [...contractRisks, ...terminationRisks, ...filteredOnboardingRisks, ...specialStatusRisks, ...retirementRisks]
     .map(r => r.employeeId)
     .filter(Boolean) as string[]
   const employees = allEmployeeIds.length > 0
@@ -548,7 +575,7 @@ export async function runRiskDetection(orgId: string) {
   const empMap = new Map(employees.map(e => [e.id, e]))
 
   // 月度任务用 monthlyKeys 去重，其他任务用 existingKeys 去重
-  const nonMonthlyRisks = [...contractRisks, ...terminationRisks, ...onboardingRisks, ...specialStatusRisks, ...retirementRisks]
+  const nonMonthlyRisks = [...contractRisks, ...terminationRisks, ...filteredOnboardingRisks, ...specialStatusRisks, ...retirementRisks]
   const toCreate = [
     ...nonMonthlyRisks.filter((r) => !existingKeys.has(`${r.employeeId}:${r.type}`)),
     ...monthlyTasks.filter((r) => !monthlyKeys.has(`${r.employeeId}:${r.title}`)),