Move Path into io.h and use for opening files. Removes dependency of gemma_lib on args. Separate Windows codepath instead of emulating POSIX functions. Plus lint fixes. PiperOrigin-RevId: 626279004
More thorough checks in sfp_test and nuq_test. nuq_test: use deterministic input generator. PiperOrigin-RevId: 625602019
PiperOrigin-RevId: 609394329