fix: resolve cron execution and optimize MySQL for system health requirements

[Salem-Al-Zuhairi]

Description

This Pull Request addresses critical issues identified in the Eramba System Health check and improves the stability of the Docker deployment.

Key Changes:

1. Cron Container Fix:
   • Adjusted the entrypoint for the cron service to use /bin/sh. This resolves startup failures where the script execution might be blocked or the path not correctly interpreted.
   
2. MySQL Optimization:
   • Increased max_allowed_packet to 128M to meet Eramba's system requirements (resolves "NOT OK" status).
   • Increased innodb_lock_wait_timeout to 200 to prevent database locks during complex operations.
   • Added several configuration flags (--sql_mode, --innodb_strict_mode, etc.) to align the containerized MySQL with the recommended settings for Eramba System Health.

3. Environment Setup:
   • Updated the default configuration to ensure a smoother "Simple Install" experience for new users.

How to test?

1. Deploy using docker-compose.simple-install.yml.
2. Access Eramba and check the System Health dashboard.
3. Verify that MySQL Allowed Packet, InnoDB Lock Timeout, and the Worker status are now showing as OK.