mtmd: deepseek-ocr v1 multi-tile (#24717)

mtmd: deepseek-ocr v1 multi-tile (#24717)

* mtmd: deepseek-ocr v1 multi-tile dynamic resolution + unified image-preprocessors for both versions (ds-ocr v1 and v2)

* remove hacky API

* fuse row into a long image

* almost working

* adapt to new preprocessor api

* rm debugging printf

* improve

* mtmd: dsocr-tiles fixes (#25481)

* ds-ocr img-preproc fuse_row tile-drop fix for multi rows and columns images

* mtmd drop the duplicate redundant img_end

* deepseekocr graph simplify CLS broadcast cleanup

* test-deepseek-ocr: relax v1 single-view tolerance; drop trailing prompt space; make DRY opt-in and n_predict model-specific (#25486)

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Co-authored-by: Saba Fallah <redacted>
Co-authored-by: Saba Fallah <redacted>