Add health checks and dependency conditions in docker-compose.yml

Introduced health checks for `netneutrality-db` to ensure proper readiness before dependent services start. Replaced static sleep in `startup.sh` with dynamic database availability checks, improving startup reliability and reducing downtime risks.

startup.sh

@@ -26,9 +26,6 @@ if [ ! -f /usr/bin/nc ]; then
     exit 1
 fi
 
-echo "Waiting 10 seconds for database to start.."
-sleep 10
-
 echo "Checking if MySQL / MariaDB is started.."
 if /usr/bin/nc -z $MYSQL_HOST $MYSQL_PORT; then
   echo "Database OK. Starting bot..";