feat: add persist feature for frontend

frontend/src/stores/token.ts

@@ -0,0 +1,30 @@
+import { defineStore } from 'pinia'
+
+interface TokenState {
+    token: string | null
+}
+
+export const useTokenStore = defineStore('token', {
+  state: (): TokenState => ({
+    token: null,
+  }),
+
+  getters: {
+    isLoggedIn: (state) => typeof state.token === 'string',
+  },
+
+  actions: {
+    login(token: string) {
+        this.token = token;
+    },
+    logout() {
+        this.token = null;
+    },
+  },
+
+  persist: {
+    key: 'ccn-token',
+    storage: localStorage,
+    pick: ['token'],
+  },
+})