float mul: full IEEE subnormal support via a unified right-shift renormalizer (right-shift the product by F+1-min(nlz,exp_base)); oracle validated bit-exact against numpy over all classes including deep underflow; all float variants rebuilt

Move source library into src/; repoint module, tool, and README paths

Add neural_matrix8 and neural_subleq8io (universal constructor); move dev scripts to tools/