feat: complete rebranding to Gemini Nexus with improved UI, proxies and documentation

index.html

@@ -2,7 +2,7 @@
 <html>
   <head>
     <meta charset="UTF-8" />
-    <title>Antigravity Manager</title>
+    <title>Gemini Nexus</title>
     <meta http-equiv="Content-Security-Policy" content="script-src 'self';" />
     <link rel="stylesheet" href="/src/styles/global.css" />
   </head>