refactor: Move files into src directory

Refactored project structure: Moved all Python modules to a src/ directory, updated imports accordingly. Added new environment variables to Dockerfile and docker-compose.yml. Removed Dockerfile.test and TODO file.

docker-compose.yml

@@ -9,6 +9,8 @@ services:
       - TZ=Europe/Paris
       - CROSSFIT_USERNAME=${CROSSFIT_USERNAME}
       - CROSSFIT_PASSWORD=${CROSSFIT_PASSWORD}
+      - TARGET_RESERVATION_TIME=${TARGET_RESERVATION_TIME}
+      - BOOKING_WINDOW_END_DELTA_MINUTES=${BOOKING_WINDOW_END_DELTA_MINUTES}
       - SMTP_SERVER=${SMTP_SERVER}
       - EMAIL_FROM=${EMAIL_FROM}
       - EMAIL_TO=${EMAIL_TO}