Move mode detection from Rsx_Mode to Rsx class

Simplify ajax batching to be mode-based instead of configurable

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

config/rsx.php

@@ -348,11 +348,6 @@ return [
 
         // Show route matching details in error pages
         'show_route_details' => env('RSX_SHOW_ROUTE_DETAILS', env('APP_DEBUG', false)),
-
-        // Disable AJAX request batching for easier debugging
-        // When true, each Ajax.call() makes an immediate individual request
-        // When false (default), requests are batched using setTimeout(0)
-        'ajax_disable_batching' => env('AJAX_DISABLE_BATCHING', false),
     ],
 
     /*