Switched to path routing. Added data management.

frontend/src/App.svelte

@@ -23,16 +23,22 @@
 
   let session = $state(null)
   let loading = $state(true)
-  let route = $state(window.location.hash || '#/')
+  let route = $state(window.location.pathname)
   let updateAvailable = $state(false)
   let mobileNavOpen = $state(false)
 
   // Check if this is a public page (no auth needed)
-  const kioskToken = $derived(window.location.hash.match(/^#\/v\/([A-Z0-9]+)/i)?.[1] ?? '')
-  const isVolunteerSignup = $derived(window.location.hash.startsWith('#/volunteer-signup'))
-  const isConfirmEmail = $derived(window.location.hash.startsWith('#/confirm/'))
+  const kioskToken = $derived(route.match(/^\/v\/([A-Z0-9]+)/i)?.[1] ?? '')
+  const isVolunteerSignup = $derived(route.startsWith('/volunteer-signup'))
+  const isConfirmEmail = $derived(route.startsWith('/confirm/'))
   const isPublicPage = $derived(!!kioskToken || isVolunteerSignup || isConfirmEmail)
 
+  function navigate(path) {
+    history.pushState(null, '', path)
+    route = path
+    mobileNavOpen = false
+  }
+
   async function checkVersion() {
     try {
       const res = await fetch('/api/version')
@@ -56,8 +62,8 @@
       startSSE()
       startSyncLoop()
     }
-    window.addEventListener('hashchange', () => {
-      route = window.location.hash || '#/'
+    window.addEventListener('popstate', () => {
+      route = window.location.pathname
       mobileNavOpen = false
     })
 
@@ -67,17 +73,17 @@
 
   function onLogin(s) {
     session = s
-    window.location.hash = '#/'
+    navigate('/')
     syncPull().then(() => { startSSE(); startSyncLoop() })
   }
 
   async function onLogout() {
     await clearSession()
     session = null
-    window.location.hash = '#/login'
+    navigate('/login')
   }
 
-  const path = $derived(route.replace(/^#/, '') || '/')
+  const path = $derived(route || '/')
   const role = $derived(session?.user?.role ?? '')
 </script>
 
@@ -107,7 +113,7 @@
     {#if mobileNavOpen}
       <div class="nav-overlay" onclick={() => mobileNavOpen = false} onkeydown={() => {}}></div>
     {/if}
-    <Nav {session} {onLogout} active={path} open={mobileNavOpen} />
+    <Nav {session} {onLogout} {navigate} active={path} open={mobileNavOpen} />
     <div class="main">
       <header class="mobile-header">
         <button class="hamburger" onclick={() => mobileNavOpen = !mobileNavOpen} aria-label="Menu">