v1.3.1 — Fix ONNX Runtime crash with q4 dtype

What's Changed

• Default dtype changed from q4f16 to q4 — fixes ONNX Runtime crash in browsers.

The Bug

q4f16 uses fp16 activations, which trigger a known graph optimization bug in ONNX Runtime WASM:

SimplifiedLayerNormFusion / InsertedPrecisionFreeCast

This happens across all fp16 models in browsers, not just Qwen2.5.

The Fix

q4 uses fp32 activations — fully compatible with ONNX Runtime WASM, no crashes.

Tradeoff

dtype	Size	Compatible
q4 (new default)	~750MB	✅ Browser + Node
q4f16 (old)	~500MB	❌ Crashes in browser
fp16	~1GB	❌ Crashes in browser

References

• transformers.js #1698
• microsoft/onnxruntime #25692