Update Space copy for PhaseB FP16 ONNX

Fix FA32M blank transcripts with NeMo fbank and length-aware ONNX

Switch WebGPU demo to FA32M fp16 ONNX

Clarify WASM fallback label

Label no-SIMD WASM fallback

Use real FP16 ONNX WebGPU artifact

Use progressive W2 ONNX model in WebGPU demo