Rende idempotente il delete path MediaMTX (404 = già rimosso).

Evita errori quando il path _air non esiste o è già stato eliminato.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/services/mediamtx/client.rb

@@ -40,7 +40,11 @@ module Mediamtx
     end
 
     def delete_path_name(path_name)
+      return true if path_name.blank?
+
       response = @conn.delete("/v3/config/paths/delete/#{CGI.escape(path_name)}")
+      return true if response.status == 404
+
       unless response.success?
         err = response.body.is_a?(Hash) ? response.body["error"] : response.body
         raise Error, "MediaMTX path delete failed: #{response.status} #{err}"