Updated all Dockerfile stage names to adhere to a consistent lowercase naming convention with underscores. This improves readability and aligns with best practices for naming Docker build stages.
This commit ensures a writable .composer directory is created with appropriate permissions. This change resolves potential permission issues when using Composer inside the container.
Otherwise phpstorm doesn't understand the paths correctly. He thinks that this is not a complete application, but a package. And when creating a class, the namespace indicates “app” with a small letter, but should be “App”.
