fix: replace deprecated apple-mobile-web-app-capable meta tag

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

calcpad-web/index.html

@@ -6,7 +6,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <meta name="description" content="CalcPad - A modern notepad calculator powered by WebAssembly" />
     <meta name="theme-color" content="#6366f1" />
-    <meta name="apple-mobile-web-app-capable" content="yes" />
+    <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-status-bar-style" content="default" />
     <meta name="apple-mobile-web-app-title" content="CalcPad" />
     <link rel="apple-touch-icon" href="/icons/icon-192.svg" />