mtmd: support MageVL-Cowork model (#31819)
* mtmd: support MageVL-Cowork model
* mtmd: keep magevl rope_freqs at model level and check its shape
The rope factors are shared by every layer, so they live in clip_model
instead of a pointer copied into each clip_layer. The loader now checks
that v.rope_freqs is F32 with d_head elements and that d_head splits
into the 4:6:6 pairs the graph expects.
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Co-authored-by: Pascal <admin@serveurperso.com>
