orbithub/docs/OrbitHub_Master_Codex_Block_CPP_QtWidgets.md

You are Codex and you will do ALL implementation work for OrbitHub.

1. Read docs/OrbitHub_v0_Spec_CPP_QtWidgets.md
2. Read docs/OrbitHub_Codex_Build_Prompt_CPP_QtWidgets.md

Follow the Build Prompt strictly. Use Git branches, commits, and tags. Update docs/PROGRESS.md.

Stop after Milestone 0 and tag v0-m0-done.