fix(kb): keep the requested chunk parameters when URL cleaning falls back

[L4XB]

Motivation / 动机

Fixes #9999. KBHelper._clean_and_rechunk_content() fell back to self.chunker.chunk(content) in two places: when cleaning is enabled but no cleaning_provider_id is given, and when get_provider_by_id fails. Both fallbacks dropped the chunk_size / chunk_overlap requested for this upload and used the shared chunker's defaults (500/100), so a request for 128/16 was stored as 500-character chunks. Since upload_document(pre_chunked_text=...) uses those chunks as they are, the later size parameters could not correct it. The normal (cleaning disabled) path already forwarded the parameters.

Modifications / 改动点

• Both fallback branches now call self.chunker.chunk(content, chunk_size=chunk_size, chunk_overlap=chunk_overlap); the warning log for the missing provider id names the parameters that are used.
• New tests/test_kb_clean_rechunk_fallback.py: with a recording chunker and a provider manager whose lookup raises, both fallback paths (and the cleaning-disabled path) receive chunk_size=128, chunk_overlap=16 and produce chunks of at most 128 characters. The two fallback tests fail on master and pass with the fix.

Verification / 验证

uv run pytest tests/test_kb_clean_rechunk_fallback.py   (3 passed)
ruff check / ruff format --check on the changed files

Checklist / 检查清单

• 我已经确认了我的更改不会引入新的错误 / I have confirmed my changes do not introduce new errors
• 我已经添加了必要的测试 / I have added the necessary tests
• 我已经更新了相关文档 (if needed) / I have updated the relevant documentation (if needed)

Summary by Sourcery

Keep requested chunking parameters when falling back to ordinary chunking during knowledge-base content processing.

Bug Fixes:

• Preserve the upload-specific chunk size and overlap when content cleaning is skipped or cleaning provider lookup fails.

Enhancements:

• Clarify fallback logging to report the chunking parameters being used.

Tests:

• Add coverage for cleaning fallbacks and the existing cleaning-disabled path to verify requested chunk parameters are retained and chunk sizes remain bounded.

[sourcery-ai]

Hey - I've reviewed your changes and they look great!

Sourcery assessment

Approved.

---

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

• X
• Mastodon
• LinkedIn
• Facebook

Sourcery withdrew this approval because the latest commits introduced blocking findings.