🐛 fix(calendar-web): initialize auth store on mount

The demo banner was showing even after login because authStore.initialize()
was never called. Now auth state is properly loaded from stored tokens.

apps/calendar/apps/web/src/routes/(app)/+layout.svelte

@@ -590,6 +590,9 @@
 	}
 
 	onMount(async () => {
+		// Initialize auth state from stored tokens
+		await authStore.initialize();
+
 		// Initialize split-panel from URL/localStorage
 		splitPanel.initialize();