Add favicon PNGs, Apple touch icon, and PWA webmanifest

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

layouts/partials/head.html

@@ -19,8 +19,9 @@
 {{- end }}
 
 <link rel="icon" type="image/svg+xml" href="/assets/roux-mark.svg" />
-<link rel="apple-touch-icon" href="/assets/roux-mark.svg" />
-<link rel="mask-icon" href="/assets/roux-mark.svg" color="#8a3322" />
+<link rel="icon" type="image/png" sizes="32x32" href="/favicon-32.png" />
+<link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
+<link rel="manifest" href="/site.webmanifest" />
 <meta name="theme-color" content="#f1ebe0" />
 
 <link rel="preconnect" href="https://fonts.googleapis.com" />