Initialize React Frontend with Bootstrap and Scalable Structure

Set up the initial React project in the repository for the Digital Watermarking Service and configure it for scalable development and seamless UI integration.

### Tasks
- [ ] Initialize a new React app using Create React App or Vite
- [ ] Install and configure Bootstrap and React-Bootstrap for consistent UI styling
- [ ] Set up React Router DOM for page navigation
- [ ] Establish a clean folder structure for components, pages, services, context, and styles
- [ ] Add .env.example with placeholders for environment variables
- [ ] Add npm/yarn scripts for easy development and build
- [ ] Write a detailed frontend README.md covering setup and best practices

**Acceptance Criteria:**
- App compiles and runs successfully on `localhost:3000`
- Folder structure supports future feature expansion
- Bootstrap styles load by default and are ready for use
- Documentation is up-to-date and accurate