chore(infra): remove --platform build flags from Dockerfiles

[joornby-angel]

Summary by CodeRabbit

• Chores

  • Standardized container platform settings across services for more consistent multi-architecture builds.
  • Minor formatting cleanups (e.g., ensured newline at end of files).

• Refactor

  • Control Plane now defaults to production mode, exposes port 3001, and runs with an explicit startup command for more predictable runtime behavior.

Checklist

• [ ] I have discussed my proposed changes in an issue and have received approval to proceed. - Issue #2241
• [x] I have followed the coding standards of the project.
• [ ] Tests or benchmarks have been added or updated.
• [ ] Documentation has been updated on https://github.com/wundergraph/cosmo-docs.
• [x] I have read the Contributors Guide.