feat(branding): update app icons and favicons to negative space leaf monogram

index.html

@@ -3,13 +3,16 @@
   <head>
     <meta charset="UTF-8" />
     <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="shortcut icon" href="/favicon.ico" />
+    <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
     <link rel="manifest" href="/manifest.json" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
     <meta name="theme-color" content="#09090b" />
     <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="Focus" />
-    <link rel="apple-touch-icon" href="/apple-touch-icon.png" />
     <meta name="description" content="Focus — 极速词流专注器" />
     <title>Focus</title>
   </head>