Add production Docker setup and update backend/frontend configs

Introduces .dockerignore, production Dockerfile and nginx config for frontend, and refactors docker-compose.yml for multi-service deployment. Updates backend and frontend code to support public API tagging, improves refund handling, adds test email endpoint, and migrates Orval config to TypeScript. Removes unused frontend Dockerfile and updates dependencies for React Query and Orval.

frontend/src/api/legacy/models/User.ts

@@ -2,7 +2,7 @@
 // User API model for searching users by username
 // Structure matches other model files (see order.js for reference)
 
-import Client from '../legacy/Client';
+import Client from '../Client';
 
 const API_BASE_URL = "/account/users";
 

frontend/src/context/UserContext.tsx

@@ -1,6 +1,6 @@
 import React, { createContext, useState, useEffect } from 'react';
 
-import userAPI from '../api/models/User';
+import userAPI from '../api/legacy/models/User';
 
 // definice uživatele
 export interface User {