feat(P19AI1-1,P19AI1-2): 实现AI建议引擎与权限门禁后端

server/src/services/featureFlags/index.js

@@ -1,4 +1,5 @@
 const FEATURE_FLAG_KEYS = {
+  aiAssist: "ai_assist",
   erpSync: "erp_sync",
   invoiceVerification: "invoice_verification",
   leaveHolidayCalendar: "leave_holiday_calendar",
@@ -55,6 +56,10 @@ function sanitizeDepartmentIds(value) {
 }
 
 function resolveEnvGate(config, flagKey) {
+  if (flagKey === FEATURE_FLAG_KEYS.aiAssist) {
+    return Boolean(config.aiAssistEnabled);
+  }
+
   if (flagKey === FEATURE_FLAG_KEYS.erpSync) {
     return Boolean(config.erpSyncEnabled);
   }