Improve security

vue/src/main.js

@@ -1,8 +1,28 @@
 import './assets/main.css'
 
+import axios from 'axios'
 import { createApp } from 'vue'
 import App from './App.vue'
 import router from './router'
+
+// A 401 means the server has rejected the token (missing, expired, or
+// revoked via logout/token_version bump elsewhere). Drop the stale session
+// and send the user back to login rather than leaving them on a page where
+// every request silently fails.
+axios.interceptors.response.use(
+  (response) => response,
+  (error) => {
+    if (error.response?.status === 401) {
+      localStorage.removeItem('user-token')
+      localStorage.removeItem('user-id')
+      if (router.currentRoute.value.name !== 'login') {
+        router.push({ name: 'login' })
+      }
+    }
+    return Promise.reject(error)
+  }
+)
+
 const app = createApp(App)
 
 app.use(router)