`.github`: add some protobuf instructions to `copilot_instructions.md`#29149

Merged

WillemKauf merged 2 commits intoredpanda-data:devfrom

WillemKauf:github_copilot_instr

Jan 13, 2026

Commits on Jan 5, 2026

`.github`: add Protobuf guidance to `copilot-instructions.md`
WillemKauf
committed
`.github`: re-enforce use of `clang_format` before committing C++ changes
WillemKauf
committed