midman-model

What it does: MidManModel, the decoder-only transformer built from a ModelConfig. Construction fails unless the parameters add up to exactly what the config counts.

Example: model.loss(&inputs, &targets, batch, seq)?.backward()? gives gradients for every parameter. forward_traced also returns every layer's attention.

Status: done and tested, including a gradient check through the whole network and bit-for-bit reproducible training.