fix(docker): correct bash syntax in postgres backup command

The command was using incorrect quote escaping which could cause issues with variable expansion and file deletion. Fixed by using single quotes for the outer string and proper escaping for date command substitution.

docker-compose.yml

@@ -138,12 +138,12 @@ services:
       - ./pg_backups:/pg_backups #host dir for backups files
     #setup bassh loop to backup data evey 24h
     command: >
-          bash -c "while true; do
-            sleep 86400;
-            PGPASSWORD=$$POSTGRES_PASSWORD pg_dump -h worklenz_db -U $$POSTGRES_USER -d $$POSTGRES_DB \
-            > /pg_backups/worklenz_db_$(date +%Y-%m-%d_%H-%M-%S).sql;
-            find /pg_backups -type f -name '*.sql' -mtime +30 -delete;
-          done"
+           bash -c 'while true; do
+              sleep 86400;
+              PGPASSWORD=$$POSTGRES_PASSWORD pg_dump -h worklenz_db -U $$POSTGRES_USER -d $$POSTGRES_DB \
+              > /pg_backups/worklenz_db_$$(date +%Y-%m-%d_%H-%M-%S).sql;
+              find /pg_backups -type f -name "*.sql" -mtime +30 -delete;
+            done'
     restart: unless-stopped
     networks:
       - worklenz