Bump namedivider-python to 0.4.2 in uv.lock

[derek73]

namedivider-python 0.4.2 was released 2026-10-12. pyproject floats namedivider-python>=0.4, so fresh [ja] installs already get it, but CI's ja-extra job installs from uv.lock, which still pinned 0.4.1.

What moves: only the namedivider-python entry in uv.lock (0.4.1 → 0.4.2).

Relevance of the release to us:

• Official Python 3.15 support. The ja-extra matrix already runs 3.11 and 3.15, so this replaces an unsupported combination with a supported one.
• SHA-256 verification of the standard model and dictionary caches, with the standard cache paths reserved. This only affects custom dictionaries or models placed at those paths. locales/ja.py constructs the default BasicNameDivider() / GBDTNameDivider() only, which upstream says need no migration.
• Deprecated pickle dictionaries and download_*_if_needed() helpers. We use neither.

Verified locally (py3.11, namedivider 0.4.2): uv run pytest: 16,645 passed, 89 skipped, 3 xfailed. The namedivider-backed segmenter tests ran. The only namedivider-related skip is the not-installed error path. The GBDT path, which downloads its model on first use, is not exercised locally.

No release-log bullet: the lock is not shipped, and the user-facing floor (>=0.4) is unchanged.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.02%. Comparing base (6fea164) to head (f18fdc4).

Additional details and impacted files

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##           master     #669   +/-   ##
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  Coverage   99.02%   99.02%           
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  Files          46       46           
  Lines        4534     4534           
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  Hits         4490     4490           
  Misses         44       44           

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