QLoRA training reached VAE encode then failed: the ZImagePipeline loads the VAE in
bf16, but the image tensor was fed as float32 -> conv2d "Input type (float) and bias
type (BFloat16) should be the same". Feed the VAE its own weight dtype.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RdMufYvtTbtGDWsiZVoXce