- make_test_spec() for all 500 samples was the real bottleneck that made
swe_bench_verified appear stuck at 'Processing records: 0%' even when all
instance images were already loaded locally.
- Now image names are computed directly from instance IDs, matching the
swebench naming convention. Local images are listed once and missing ones
are reported immediately. make_test_spec is only called for images that
actually need to be built.
- With 500 pre-loaded images, build_images() now completes in ~45s instead of
hanging indefinitely.
Also add bash/diagnose_swe_images.py for quickly checking which images are
missing locally.
