refactor(config): Update API and webhook URLs

Update .env.example files with new API and webhook URLs.
Refactor next.config.js for base path configuration.

Author: abbasiandev

backend/.env.example

@@ -1,6 +1,6 @@
 # Telegram
 BOT_TOKEN=your_bot_token_here
-WEBHOOK_URL=https://yourname.pythonanywhere.com/webhook
+WEBHOOK_URL=https://subix.k.jrnm.app/webhook
 
 # JWT
 SECRET_KEY=change_this_to_random_64_char_string

frontend/.env.local.example

@@ -1 +1 @@
-NEXT_PUBLIC_API_URL=https://yourname.pythonanywhere.com
+NEXT_PUBLIC_API_URL=https://subix.k.jrnm.app

frontend/next.config.js

@@ -3,8 +3,7 @@ const nextConfig = {
   output: "export",
   trailingSlash: true,
   images: { unoptimized: true },
-  // Set basePath if deploying to /repo-name on GitHub Pages
-  // basePath: "/subix",
+  basePath: "/Subix",
 };
 
 module.exports = nextConfig;