Added mobile hamburger.

frontend/src/App.svelte

@@ -23,6 +23,7 @@
   let loading = $state(true)
   let route = $state(window.location.hash || '#/')
   let updateAvailable = $state(false)
+  let mobileNavOpen = $state(false)
 
   // Check if this is a kiosk token URL before doing anything else
   const kioskToken = $derived(window.location.hash.match(/^#\/v\/([A-Z0-9]+)/i)?.[1] ?? '')
@@ -52,6 +53,7 @@
     }
     window.addEventListener('hashchange', () => {
       route = window.location.hash || '#/'
+      mobileNavOpen = false
     })
 
     // Periodically check for updates
@@ -92,8 +94,18 @@
   <GateUI {session} {onLogout} />
 {:else}
   <div class="layout">
-    <Nav {session} {onLogout} active={path} />
+    <!-- svelte-ignore a11y_no_static_element_interactions -->
+    {#if mobileNavOpen}
+      <div class="nav-overlay" onclick={() => mobileNavOpen = false} onkeydown={() => {}}></div>
+    {/if}
+    <Nav {session} {onLogout} active={path} open={mobileNavOpen} />
     <div class="main">
+      <header class="mobile-header">
+        <button class="hamburger" onclick={() => mobileNavOpen = !mobileNavOpen} aria-label="Menu">
+          <span></span><span></span><span></span>
+        </button>
+        <span class="mobile-brand">Turn<span class="accent">pike</span></span>
+      </header>
       {#if path === '/' || path === ''}
         {#if role === 'volunteer_lead'}
           <ScheduleBoard {session} />