Add MLX 5-bit, floating formats and calibrated APEX including Mini

Add three APEX GGUF options to the checkpoint explorer

Add MLX 6-bit and 8-bit, local API recipes and client requests

Add Q3_K_L, Q4_0 and Q5_0 to checkpoint explorer

Add Q3_K_S and Q5_K_S to checkpoint explorer

Add Occamy checkpoint explorer with downloads and deployment recipes