feat(scheduling,admin,today): week-range queries, file size limits, mobile nav UX

- Expand exceptional application query to Monday of start week
- Add 20MB file size limit with visual feedback in ImageUpload
- Reorder admin nav links, add burger badge, slide transition + backdrop
- Fetch week-range working/available hours, add closing time indicator
- Skip lunch protection for days <= 5h via shouldApplyLunchProtection
- Extract formatDateISO to shared utils

frontend/src/lib/components/layout/NavBar.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
 	import { onMount, onDestroy } from 'svelte';
+	import { slide } from 'svelte/transition';
 	import { navigating, page } from '$app/stores';
 	import { goto } from '$app/navigation';
 	import { authStore } from '$lib/stores/auth.svelte';
@@ -9,13 +10,13 @@
 	// Centralized link definition
 	const links = [
 		{ href: '/', label: 'Home', showWhen: 'non-admin', width: 'w-12' },
+		{ href: '/today', label: 'Today', showWhen: 'admin', width: 'w-28' },
+		{ href: '/admin/schedule', label: 'Schedule', showWhen: 'admin', width: 'w-20' },
 		{ href: '/prices', label: 'Price List', showWhen: 'guest', width: 'w-20' },
 		{ href: '/schedule', label: 'My Schedule', showWhen: 'auth-not-admin', width: 'w-24' },
 		{ href: '/book', label: 'Book an appointment', showWhen: 'non-admin', width: 'w-36' },
 		{ href: '/portfolio', label: 'Portfolio', showWhen: 'always', width: 'w-20' },
 		{ href: '/admin', label: 'Admin Dashboard', showWhen: 'admin', width: 'w-28' },
-		{ href: '/today', label: 'Today', showWhen: 'admin', width: 'w-28' },
-		{ href: '/admin/schedule', label: 'Schedule', showWhen: 'admin', width: 'w-20' },
 		{ href: '/contact', label: 'Contact', showWhen: 'non-admin', width: 'w-16' },
 		{ href: '/account', label: 'My Account', showWhen: 'auth', width: 'w-24' }
 	];
@@ -178,7 +179,7 @@
 
 			<!-- Mobile: Burger -->
 			<div class="flex items-center md:hidden">
-				<button onclick={toggleMenu} class="focus:outline-none" aria-label="Toggle menu">
+				<button onclick={toggleMenu} class="relative focus:outline-none" aria-label="Toggle menu">
 					<svg class="h-6 w-6 text-gray-700" fill="none" stroke="currentColor" viewBox="0 0 24 24">
 						<path
 							stroke-linecap="round"
@@ -187,14 +188,31 @@
 							d="M4 6h16M4 12h16M4 18h16"
 						/>
 					</svg>
+					{#if unreadCount > 0 && !mobileMenuOpen}
+						<span
+							class="absolute -top-1 -right-1.5 flex h-4 w-4 items-center justify-center rounded-full bg-red-500 text-[10px] font-bold text-white"
+						>
+							{unreadCount > 9 ? '9+' : unreadCount}
+						</span>
+					{/if}
 				</button>
 			</div>
 		</div>
 	</div>
 
+	{#if mobileMenuOpen}
+		<div
+			class="fixed inset-0 top-16 bg-black/30 backdrop-blur-[1px] md:hidden"
+			onclick={toggleMenu}
+		></div>
+	{/if}
+
 	<!-- Mobile Menu -->
 	{#if mobileMenuOpen}
-		<div class="border-b border-gray-200 bg-background md:hidden">
+		<div
+			transition:slide={{ duration: 100 }}
+			class="relative z-50 border-b border-gray-200 bg-background md:hidden"
+		>
 			<div class="space-y-1 px-2 pt-2 pb-3">
 				{#each links as link}
 					{#if canShow(link)}