Match Qwen head-chunked attention execution

docs/issue113-head-chunk/off-product/cold.json

@@ -0,0 +1 @@
+{"case":"cold","prompt":[248045,8678,198,24342,286,4879,369,716,310,3238,13,13262,678,7047,9522,321,10419,11,6992,5774,310,279,16198,1973,24366,24150,362,13,248046,198,248045,846,198,2427,494,799,310,5600,13,248046,198,248045,74455,198,248068,198],"tokens":[760,1156,6587,728,310,1698,494,799,310,5600,13,1061],"cached":0,"state_sha256":"eb61c20e4a89bb55c0284d86587966af49d6c601e5421b50eff0762ecf6842b1"}