model : support for Prism Bonsai 2 27B (#29600)
* Runtime support for Prism Bonsai 2 27B
Assisted-by: Claude Code
* address prism hadamard runtime feedback
* move hadamard tensors into method, define folded weight
* load_* hadamard fixes
* cont : clean-up
* conversion cleanup
Assisted-by: Claude Code
* prism hadamard key and methods for converter
Assisted-by: Claude Code
* address review bot feedback
Assisted-by: Claude Code
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Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
