fix: 修复获取文本未保留换行问题

[LollipopsAndWine]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

@@            Coverage Diff             @@
##              dev     #284      +/-   ##
==========================================
- Coverage   90.68%   89.53%   -1.15%     
==========================================
  Files         116       81      -35     
  Lines        6914     5564    -1350     
==========================================
- Hits         6270     4982    -1288     
+ Misses        644      582      -62     

Files with missing lines	Coverage Δ
llm_web_kit/extractor/html/recognizer/text.py	100.00% <100.00%> (ø)

... and 51 files with indirect coverage changes

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[yogacc33]

return txt.strip().replace('\r\n', '\n').replace('\n', '\n') 原来的text1内容是带转义的吗，这里直接换成不转义的字符\n吗？

[LollipopsAndWine]

这里把文本中的双斜杠\n换成单斜杠\n是因为要保留换行，只有单斜杠\n才能生成有换行的文本，然后生成markdown时有换行效果