feat: add complete favicon set for Google Search and browsers

- Add PNG favicons (16x16, 32x32, 180x180, 192x192, 512x512)
- Add apple-touch-icon for iOS devices
- Add site.webmanifest for Android/PWA support
- Update BaseLayout with proper favicon meta tags
- Add theme-color meta tag

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: kitfunso

public/android-chrome-192x192.png

@@ -0,0 +1,19 @@
+{
+  "name": "Boring Math Calculators",
+  "short_name": "Boring Math",
+  "icons": [
+    {
+      "src": "/android-chrome-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png"
+    },
+    {
+      "src": "/android-chrome-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    }
+  ],
+  "theme_color": "#07070a",
+  "background_color": "#07070a",
+  "display": "standalone"
+}

public/android-chrome-512x512.png

@@ -88,6 +88,11 @@ const ogImageURL = ogImage
 
     <!-- Favicon -->
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+    <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png" />
+    <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png" />
+    <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
+    <link rel="manifest" href="/site.webmanifest" />
+    <meta name="theme-color" content="#07070a" />
 
     <!-- Google Analytics -->
     <Analytics />