### Summary
Closes#18414.
`rag/res/term.freq` is not shipped, and both term-weight implementations
therefore assigned the same `300` fallback frequency to every lowercase
Latin token. With no tokenizer frequency, NER, or POS signal, function
words and content words received identical lexical boosts.
This PR adds the same bounded out-of-vocabulary prior to Python and Go:
- Use it only when the explicit DF dictionary or tokenizer has no
frequency.
- Count Latin, Greek, and Cyrillic letters, including uppercase and
accented forms.
- Keep the existing frequency of `300` for words up to three letters,
halve it every two additional letters, and clamp it at `10`.
- Reject digits, underscores, and logographic terms so Chinese and other
existing fine-grained-tokenizer paths are unchanged.
- Treat an absent optional `term.freq` as the supported fallback path
without a startup warning, while still logging inaccessible or malformed
dictionaries.
A corpus-derived table was intentionally not added: that would require
provenance/licensing decisions, language detection, and handling
cross-language homographs. The bounded prior is deterministic,
dependency-free, and fixes the equal-weight degradation for
whitespace-delimited alphabetic languages without claiming
corpus-specific precision.
Python and Go consume one shared fixture covering ASCII, uppercase,
accented Latin, Greek, Cyrillic, separators, invalid mixed tokens, and a
CJK non-match. Both sides also verify the issue's ordering (`was <
largest < supplier < equipment`) and that an explicit dictionary entry
still takes precedence.
Co-authored-by: Loong <184861530+yzl0ng@users.noreply.github.com>
## Summary
- Skip MinerU `header`, `footer`, and `page_number` blocks when
converting `content_list.json` into sections.
- Ignore unsupported block types explicitly so future MinerU output
types cannot re-emit the previous text block.
Fixes duplicate text in General/naive chunks when parsing PDFs via
MinerU (reported with repeated page headers and body text in slices).
Closes#15335
## Test plan
- [x] `pytest test/unit_test/deepdoc/parser/test_mineru_parser.py -v`
(4/4 passed)
