build(docker): optimize docker setup and compose configuration

- Split Dockerfile into multi-stage build to reduce final image size
- Update docker-compose.yml with restart policies and health checks
- Improve .dockerignore files for both frontend and backend
- Fix MinIO bucket creation script to use 'alias set' instead of deprecated command
- Enhance PostgreSQL healthcheck configuration

worklenz-backend/.dockerignore

@@ -1,5 +1,9 @@
 node_modules
 npm-debug.log
-build
 .scannerwork
 coverage
+.dockerignore
+.git
+*.md
+tests
+