create_entity + update_entity created the `scratch` temp dir inside one
try/finally but cleaned it up in a separate one. Validation HTTPExceptions
raised by _safe_zip_extract (zip_unsafe_path, zip_too_large_uncompressed)
or the BadZipFile→422 conversion exited the first scope, and the second
finally was never entered → temp dir leaked on every failed upload.
Devin flagged this on the F2 commit. The leak pre-existed (zip_unsafe_path
was the original vector); F2 added zip_too_large_uncompressed to the same
broken cleanup path. Fixed by collapsing scratch creation + cleanup into
one outer try/finally that covers both extraction AND metadata/bake; the
inner try/except/finally still handles BadZipFile→422 + tmp file cleanup.
Same restructure in update_entity. Regression test
`test_scratch_dir_cleaned_up_after_failed_extraction` triggers a
zip_unsafe_path 422 and asserts tmp/agnes_store_* contains no leaked
dirs.
f0d091f721