nx_zimage_dequant_block.nx

nx_zimage_dequant_block.nx -- dequant a block of REAL Z-Image weight DATA into f32, sovereignly. sd-server -> Nishi migration: extends the real-weight bridge from METADATA to actual WEIGHT DATA. Reads the real `Z-Image_Qwen_3_4b-Q6_K.gguf`, locates token_embd.weight (Q6_K, ggml_type 14), computes its data location (hdr.data_off + ti.offset -- it's the first tensor so this is at the very start of the data section, inside our bounded prefix), and dequantizes the FIRST Q6_K super-block (256 real embedding values) with our own `nx_q6_k_to_f32`. Proves: real Z-Image quantized weights -> our dequant -> real, finite, nonzero f32. Writes the first sample values to /tmp/zimg_dq.txt. license_tier: ORIGINAL