feat(ops-web/auth): add remember-me with session/local storage split

Persistent logins land in localStorage, ephemeral ones in sessionStorage,
and we recall the last username + remember preference on the login form.
Also propagate the indigo brand color through the antd ConfigProvider
theme token so the side nav and avatar match the redesigned login.

apps/ops-web/src/App.vue

@@ -1,5 +1,5 @@
 <template>
-  <a-config-provider>
+  <a-config-provider :theme="themeConfig">
     <a-app>
       <router-view />
     </a-app>
@@ -13,6 +13,15 @@ import { useAuthStore } from "@/stores/auth";
 
 const auth = useAuthStore();
 
+const themeConfig = {
+  token: {
+    colorPrimary: "#4f46e5",
+    colorLink: "#4f46e5",
+    colorInfo: "#4f46e5",
+    borderRadius: 6,
+  },
+};
+
 onMounted(() => {
   if (!auth.initialized) auth.hydrate();
 });