Strengthen `real_weights_load_when_available` in the smoke suite:
- search for `pose_v1.safetensors` under the three plausible test
cwds (crate dir, `v2/`, repo root) so the test exercises the real
loader regardless of where `cargo test` is invoked from
- after inference, chunk the flat 34-scalar output into 17 (x, y)
pairs and assert each pair is finite, non-NaN, and inside the
sigmoid range [0, 1]
- keep the skip path with a clear message when the safetensors blob
isn't on disk (so the suite still passes on a fresh appliance
install where weights ship separately)
This complements the inline unit tests in `src/inference.rs` — those
exercise the loader / forward-pass plumbing, the smoke test exercises
the public crate surface.
51fd326aae