Refactor the JavaScript code to use a single modal for both forex and stock profiles. Update error handling to display server error messages. Remove unused app.py and fetch.py files. Adjust various routes and strategies for consistency.
- Update `app.py` to include backtesting routes and improve blueprint registration.
- Modify templates to include an active page parameter for navigation highlighting.
- Remove unused `crypto_data.py` and `api_crypto.py`.
- Add new backtesting-related files and templates.