…dup and harm categories

… fix imports and ordering

- _RemoteDatasetLoader._fetch_zip_from_url:
  - keyword-only args (source, inner_files, cache)
  - streams download (requests stream=True + iter_content) to avoid
    double-buffering large archives
  - md5-keyed disk cache under DB_DATA_PATH / seed-prompt-entries when
    cache=True; named temp file otherwise (cleaned up after parse)
  - validates each inner_files extension against FILE_TYPE_HANDLERS;
    raises ValueError with a member preview if an inner file is missing
  - parses inner files via FILE_TYPE_HANDLERS and returns parsed dicts,
    so the open ZipFile never escapes the worker thread
  - adds the missing import zipfile that broke the previous commit
- _MICDataset:
  - drops unused io / json / requests imports (helper handles them)
  - delegates download + parse to the helper; only owns the seed
    construction loop
  - guards non-string Q values (in addition to NaN moral values)
  - forwards cache from fetch_dataset_async to the helper
  - factors authors into AUTHORS class constant
- Tests:
  - test_moral_integrity_corpus_dataset.py: stops mocking requests.get
    directly; patches _fetch_zip_from_url to return parsed dicts so
    tests don't depend on the helper's internal shape
  - adds test_fetch_dataset_non_string_q and
    test_fetch_dataset_passes_cache_flag
  - hoists imports into the right groups so ruff I001 stops firing
  - removes trailing whitespace / extra newlines
- test_remote_dataset_loader.py: adds TestFetchZipFromUrl covering
  happy path, on-disk caching (hits 1 network call across 2 fetches),
  cache=False does not persist, missing inner file raises ValueError,
  unsupported extension raises ValueError

Verified live against the real MIC.zip: 35,408 unique seeds across
all 6 moral foundations in ~2.4s cold / ~1.3s warm. All 559 dataset
unit tests pass; ruff clean.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Use tempfile.NamedTemporaryFile instead of fixed temp_audio.wav
  to prevent concurrent call collisions
- Wrap Azure upload in try/finally to ensure temp file is always
  deleted even when upload fails
- Add regression test to verify cleanup on upload failure

Fixes microsoft#1894