fix(auth): defer environment context fetch until token is available

frontend/src/routes/+layout.svelte

@@ -23,7 +23,6 @@
 @INVARIANT: Login route bypasses shell; all other routes are wrapped by ProtectedRoute.
 -->
 <script>
-    import { onMount } from 'svelte';
     import '../app.css';
     import Navbar from '../components/Navbar.svelte';
     import Footer from '../components/Footer.svelte';
@@ -36,7 +35,6 @@
     import AssistantChatPanel from '$lib/components/assistant/AssistantChatPanel.svelte';
     import { t } from '$lib/i18n';
     import {
-        initializeEnvironmentContext,
         isProductionContextStore,
         selectedEnvironmentStore
     } from '$lib/stores/environmentContext.js';
@@ -47,12 +45,6 @@
     $: isExpanded = $sidebarStore?.isExpanded || true;
     $: isProductionContext = $isProductionContextStore;
     $: selectedEnvironment = $selectedEnvironmentStore;
-
-    onMount(async () => {
-        if (!isLoginPage) {
-            await initializeEnvironmentContext();
-        }
-    });
 </script>
 
 <Toast />