add: adding mobile manifest

Author: mallory-scotton

assets/icons/icon-192.png

@@ -31,6 +31,14 @@
     <meta name="twitter:image" content="https://graphical-playground.com/assets/preview-image.png">
     <meta name="twitter:image:alt" content="Graphical Playground — Build Graphics Engines from Scratch">
 
+    <!-- ── Web App Manifest ── -->
+    <link rel="manifest" href="manifest.webmanifest">
+    <meta name="theme-color" content="#3b82f6">
+    <meta name="apple-mobile-web-app-capable" content="yes">
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
+    <meta name="apple-mobile-web-app-title" content="GP">
+    <link rel="apple-touch-icon" href="assets/icons/icon-192.png">
+
     <!-- ── Favicons & Assets ── -->
     <link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
     <link rel="stylesheet" href="style.css">

assets/icons/icon-512-maskable.png

@@ -0,0 +1,30 @@
+{
+  "name": "Graphical Playground",
+  "short_name": "GP",
+  "description": "Build graphics-engine systems from scratch — creative coding & canvas experiments.",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "orientation": "any",
+  "background_color": "#0a0a0f",
+  "theme_color": "#3b82f6",
+  "categories": ["education", "developer tools"],
+  "icons": [
+    {
+      "src": "/assets/icons/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png"
+    },
+    {
+      "src": "/assets/icons/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    },
+    {
+      "src": "/assets/icons/icon-512-maskable.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "maskable"
+    }
+  ]
+}