feat(files): fix expires_after API shape

[ashwinb]

This was just quite incorrect. See source here: https://platform.openai.com/docs/api-reference/files/create

[mattf]

@ashwinb @raghotham this is what you'd expect the api def to be, but it doesn't work.

a lot of time went into figuring out the shape that works for fastapi. unfortunately it all got condensed to a terse comment - https://github.com/llamastack/llama-stack/pull/3604/files#diff-6b15e491d326a7148daaefcf182dbb2b1aabd88efdfada7c4973c58f9ce1e0b2L116

run minio -

$ podman run --rm -it -p 9000:9000 minio/minio server /data
...

run files=remote::s3 stack -

$ S3_AUTO_CREATE_BUCKET=true S3_ENDPOINT_URL=http://localhost:9000 AWS_ACCESS_KEY_ID=minioadmin AWS_SECRET_ACCESS_KEY=minioadmin S3_BUCKET_NAME=llama-stack-files uv run llama stack build --image-type venv --providers files=remote::s3 --run

run tests -

$ uv run pytest tests/integration/files --stack-config http://localhost:8321 --runxfail -k expires_after
==================================================== test session starts ====================================================
platform linux -- Python 3.12.11, pytest-8.4.2, pluggy-1.6.0 -- .../.venv/bin/python
cachedir: .pytest_cache
metadata: {'Python': '3.12.11', 'Platform': 'Linux-6.16.7-200.fc42.x86_64-x86_64-with-glibc2.41', 'Packages': {'pytest': '8.4.2', 'pluggy': '1.6.0'}, 'Plugins': {'html': '4.1.1', 'anyio': '4.9.0', 'timeout': '2.4.0', 'cov': '6.2.1', 'asyncio': '1.1.0', 'nbval': '0.11.0', 'socket': '0.7.0', 'json-report': '1.5.0', 'metadata': '3.1.1'}}
rootdir: ...
configfile: pyproject.toml
plugins: html-4.1.1, anyio-4.9.0, timeout-2.4.0, cov-6.2.1, asyncio-1.1.0, nbval-0.11.0, socket-0.7.0, json-report-1.5.0, metadata-3.1.1
asyncio: mode=Mode.AUTO, asyncio_default_fixture_loop_scope=None, asyncio_default_test_loop_scope=function
collected 6 items / 4 deselected / 2 selected                                                                               

tests/integration/files/test_files.py::test_expires_after FAILED                                                      [ 50%]
tests/integration/files/test_files.py::test_expires_after_requests FAILED                                             [100%]

========================================================= FAILURES ==========================================================
____________________________________________________ test_expires_after _____________________________________________________
tests/integration/files/test_files.py:98: in test_expires_after
    assert uploaded_file.expires_at is not None
E   AssertionError: assert None is not None
E    +  where None = FileObject(id='file-e2053ce7cf3b4d6cbd3ffadec887d4db', bytes=18, created_at=1759226124, filename='expires_after.txt', object='file', purpose='assistants', status=None, expires_at=None, status_details=None).expires_at
--------------------------------------------------- Captured stdout setup ---------------------------------------------------

instantiating llama_stack_client
llama_stack_client instantiated in 0.091s
________________________________________________ test_expires_after_requests ________________________________________________
tests/integration/files/test_files.py:144: in test_expires_after_requests
    assert result.get("expires_at") == result["created_at"] + 4545
E   AssertionError: assert None == (1759226124 + 4545)
E    +  where None = <built-in method get of dict object at 0x7f308c66e000>('expires_at')
E    +    where <built-in method get of dict object at 0x7f308c66e000> = {'bytes': 26, 'created_at': 1759226124, 'expires_at': None, 'filename': 'expires_after_with_requests.txt', ...}.get
=================================================== slowest 10 durations ====================================================
0.28s call     tests/integration/files/test_files.py::test_expires_after
0.18s setup    tests/integration/files/test_files.py::test_expires_after
0.07s call     tests/integration/files/test_files.py::test_expires_after_requests
0.01s setup    tests/integration/files/test_files.py::test_expires_after_requests

(2 durations < 0.005s hidden.  Use -vv to show these durations.)
================================================== short test summary info ==================================================
FAILED tests/integration/files/test_files.py::test_expires_after - AssertionError: assert None is not None
FAILED tests/integration/files/test_files.py::test_expires_after_requests - AssertionError: assert None == (1759226124 + 4545)
======================================== 2 failed, 4 deselected, 1 warning in 0.78s =========================================

test directly with curl, note expires_at comes back as null -

curl http://localhost:8321/v1/files \                                                                 
  -H "Authorization: Bearer NOPE" \
  -F purpose="assistants" \
  -F file="@LICENSE" \
  -F 'expires_after[anchor]="created_at"' \
  -F 'expires_after[seconds]=4500'

{"object":"file","id":"file-b8cea292fd7048f98d20d4b2bb31a71e","bytes":1087,"created_at":1759226200,"expires_at":null,"filename":"LICENSE","purpose":"assistants"}

there are no expires_after unit tests because the crux is passing through fastapi. we still need to split out the ci-tests distro so we can add the remote::s3 integration tests to the ci suite.

please revert this.

[ashwinb]

Let me see if I can fix this forward early morning (unless you have reverted it?)

[mattf]

Let me see if I can fix this forward early morning (unless you have reverted it?)

i have not reverted it