fix: fix lost token validation

frontend/src/router/index.ts

@@ -1,5 +1,6 @@
 import { createRouter, createWebHistory } from 'vue-router'
 import { useTokenStore } from '@/stores/token'
+import { tokenValid as apiCommonTokenValid } from '@/api/common'
 
 import Home from '@/views/Home.vue'
 import Collection from '@/views/Collection.vue'
@@ -33,9 +34,19 @@ const router = createRouter({
   routes: routes,
 });
 
-router.beforeEach((to, _from) => {
-  // Only check for those flagged.
+router.beforeEach(async (to, _from) => {
   const token = useTokenStore();
+
+  // Sync the local token with the server on every navigation. If the server
+  // says it's invalid (or the request fails — faithfully preserved from the
+  // legacy behaviour, where any failure cleared the token), log out so the
+  // meta checks below and the reactive nav see the logged-out state.
+  if (token.isLoggedIn) {
+    const ok = await apiCommonTokenValid(token.currentToken);
+    if (!ok) token.logout();
+  }
+
+  // Only check for those flagged.
   if (to.meta.requireLoggedInCheck) {
     if (!token.isLoggedIn) {
       return { name: 'Default', replace: true };