Rename s_arch -> sphere_arch to match SphereArch class

Rename s_arch ckpt: input embeddings are not renormalized (model.normalize_input_embed=False)

Rename SFM tinygsm checkpoints: arch_truncated_{fixed,adaptive}_{renorm|no_renorm}

Upload checkpoint: tinygsm/sfm/paper_trunc_no_renorm_adaptive_ngpt.ckpt

Upload checkpoint: tinygsm/sfm/paper_trunc_no_renorm_adaptive.ckpt

Upload checkpoint: tinygsm/sfm/paper_trunc_no_renorm.ckpt

Upload checkpoint: tinygsm/sfm/sphere_dit_adaptive_no_renorm_refit50.ckpt

Upload checkpoint: tinygsm/sfm/ngpt_adaptive_refit50.ckpt