The stale artifact cleanup now runs where the mode changes, in
run_reconfigure, so a failed build after a flip cannot leave a skip
tree with full mode leftovers. Upload error hints come from the native
backend's missing_image_hint instead of platform checks in the CLI, and
idf_macro_matches takes the IDF path instead of importing the toolchain
back. The flag now errors on unsupported platforms and on a serial
--device before compiling, and the macro drift fallback warns instead
of logging at info. Also drops leftovers from the removed cache: the
parse_sdkconfig helper, the _idf_target wrapper and two stale comments.
J. Nick Koston
392d6a414c