Use scripts/station_gen_build with -B and -D SDKCONFIG so generate_and_check
does not read the station example's sdkconfig or build tree. Apply
sdkconfig.defaults and IDF_TARGET=esp32 for stable header preprocessing.
Unset GIT_DIR/GIT_INDEX_FILE (and related vars) before git subprocesses so
pre-commit and git worktrees do not mis-resolve paths after cd into scripts/.