Add favorites feature - toggle, list, and pre-fill on add

client/public/favicon.svg

@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
+  <circle cx="50" cy="50" r="45" fill="#059669"/>
+  <text x="50" y="65" font-size="50" text-anchor="middle" fill="white">🍽️</text>
+</svg>

client/public/manifest.json

@@ -0,0 +1,10 @@
+{
+  "name": "Meal Tracker",
+  "short_name": "Meals",
+  "description": "Track your daily food intake and macros",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#111827",
+  "theme_color": "#059669",
+  "icons": []
+}

client/public/service-worker.js

@@ -0,0 +1,14 @@
+const CACHE_NAME = 'meal-tracker-v1';
+const urlsToCache = ['/', '/index.html', '/assets/'];
+
+self.addEventListener('install', event => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then(cache => cache.addAll(urlsToCache))
+  );
+});
+
+self.addEventListener('fetch', event => {
+  event.respondWith(
+    caches.match(event.request).then(response => response || fetch(event.request))
+  );
+});