refactor: streamline RSVP reader for The Well of Ascension single-book focus

- Clean up legacy multi-format/CJK modules (orp, epub, samples, modals)
- Replace with lightweight pure English tokenizer and chunking engine
- Add SettingsDrawer, auto-hiding HUD, and PWA icons
- Update manifest and touch icons

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

index.html

@@ -1,15 +1,20 @@
 <!doctype html>
-<html lang="zh-CN">
+<html lang="en">
   <head>
     <meta charset="UTF-8" />
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+    <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="description" content="Focus — 极致极速 RSVP 闪屏阅读器，基于 Spritz ORP 中心锚定与自适应呼吸节奏算法，眼球完全静止，秒进专注流。" />
-    <title>Focus — 极速 RSVP 闪屏专注阅读器</title>
+    <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>
-  <body class="bg-black select-none">
-    <div id="root"></div>
+  <body class="bg-[#09090b] text-[#f4f4f5] select-none antialiased overflow-hidden">
+    <div id="root" class="h-full w-full"></div>
     <script type="module" src="/src/main.tsx"></script>
   </body>
 </html>