feat: add Grain PWA icons and favicon

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

Changed files
+2
public
+2
index.html
··· 4 4 <meta charset="UTF-8"> 5 5 <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1"> 6 6 <meta name="theme-color" content="#000000"> 7 + <link rel="icon" type="image/png" href="/favicon.png"> 8 + <link rel="apple-touch-icon" href="/icons/icon-192.png"> 7 9 <link rel="manifest" href="/manifest.json"> 8 10 <link rel="stylesheet" href="/src/styles/variables.css"> 9 11 <link rel="preconnect" href="https://fonts.googleapis.com">
public/favicon.png

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public/icons/icon-192.png

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public/icons/icon-512.png

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