The Makefile targets were renamed to a `<group>/<action>` scheme and a `missing-dot` target was added, but the Copilot instructions still referenced the old `unittests-*` targets and a non-existent `unittests` target. Contributors and agents following these instructions therefore ran commands that no longer exist. Also correct the yamllint configuration file name to `.yamllint.yaml`. Co-authored-by: Copilot <copilot@github.com>