refactor: Implement Docker, MySQL logging, and SMTP email

This commit refactors the application to run in a containerized environment using Docker and Docker Compose. It also introduces a MySQL database for logging user requests and updates the print functionality to send emails via SMTP.

Key changes:
- Added `Dockerfile` and `docker-compose.yml` for containerization.
- Integrated a MySQL database for logging user requests.
- Updated the print module to send files as email attachments via SMTP.
- Added and updated configuration files (`.env`, `.env.example`) to manage secrets and environment variables.
- Removed hardcoded credentials from version control.
- Updated `Readme.md` with new setup and execution instructions.

.env

@@ -3,8 +3,4 @@ TELEGRAM_TOKEN=TU_TOKEN_NUEVO_AQUI
 
 # Webhooks de n8n (puedes agregar más aquí en el futuro)
 WEBHOOK_CONTRATO=https://flows.soul23.cloud/webhook/DuXh9Oi7SCAMf9
-WEBHOOK_PRINT=
-WEBHOOK_VACACIONES=
-
-# --- DATABASE ---
-DATABASE_URL=mysql+mysqlconnector://user:password@db:3306/vanessa_logs
+# WEBHOOK_VACACIONES=https://... (futuro)