The previous files used make_quantizer's MovingAverageMinMaxObserver default,
whose moving average trails the real activation range. Measured on an S26 Ultra
over 500 ImageNetV2 images: 70.00% top-1 before, 71.80% after, against 72.20%
for fp32. Quantization loss drops from 2.20 points to 0.40 at the same size.
Only the v81 file is device-validated; the other four are the same code path and
calibration compiled for Hexagon versions we have no hardware for.
Add QNN a16w8 exports, one per Hexagon version (v69-v81)
