Users who downloaded ruvnet/wifi-densepose-pretrained and passed
model.safetensors / model-q4.bin / model.rvf.jsonl to --model hit a bare
"Progressive loader init failed: invalid magic at offset 0: expected
0x52564653, got 0x77455735" and were stuck — the server then silently fell
back to signal heuristics (which over-count, feeding "is it fake" reports).
The HF files are a different *format* and encoder architecture than the RVF
binary container the progressive loader expects, so they can't load directly.
Now the load-failure path detects the common cases (safetensors header,
JSONL manifest, quantized .bin blob) and emits a plain explanation naming the
format, what --model actually expects (RVF `RVFS` container from
wifi-densepose-train), and that it's continuing with heuristics — with a
pointer to #894.
Pure, testable `diagnose_model_load_error()` + 4 unit tests (run under the
default `--no-default-features` CI). Full crate unit suite: 429 + 114 passed,
0 failed.
f5d0e1e69e