中文：收口权限与中心/立项配置改造

frontend/src/utils/permission.ts

@@ -2,6 +2,7 @@ import { computed } from "vue";
 import { useAuthStore } from "../store/auth";
 import { useStudyStore } from "../store/study";
 import { TEXT } from "../locales";
+import { getProjectRole, isSystemAdmin } from "./roles";
 
 const PERMISSIONS: Record<string, string[]> = {
   "subject.create": ["ADMIN", "PM", "CRA"],
@@ -37,13 +38,11 @@ export const usePermission = () => {
   const auth = useAuthStore();
   const study = useStudyStore();
 
-  const userRole = computed(() => auth.user?.role || null);
-  const projectRole = computed(
-    () => study.currentStudyRole || (study.currentStudy as any)?.role_in_study || auth.user?.role || null
-  );
+  const systemAdmin = computed(() => isSystemAdmin(auth.user));
+  const projectRole = computed(() => getProjectRole(study.currentStudy, study.currentStudyRole));
 
   const can = (action: string): boolean => {
-    if (userRole.value === "ADMIN") return true;
+    if (systemAdmin.value) return true;
     const allowList = PERMISSIONS[action];
     if (!allowList) return false;
     if (!projectRole.value) return false;
@@ -51,7 +50,7 @@ export const usePermission = () => {
   };
 
   const reason = (action: string): string => {
-    if (userRole.value === "ADMIN") return "";
+    if (systemAdmin.value) return "";
     return REASONS[action] || TEXT.modules.permissions.default;
   };