OV-circuit unembedding-diagonal projection

Composes an attention head's full OV (and QK) circuit with the model's own embedding/unembedding matrices to get an explicit vocab-by-vocab matrix, then checks whether each token's own diagonal entry (its self-projection through the circuit) is an extreme (most negative, or most positive) value in its row/column — turning a component's weights into a directly quantified per-token directional claim, rather than a purely behavioral/functional description of what the head does.