fix: 修复空内容返回的语言详情，在176版本下language_details返回"not_defined"

[darkrush]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

@@            Coverage Diff             @@
##              dev     #300      +/-   ##
==========================================
+ Coverage   89.70%   89.88%   +0.17%     
==========================================
  Files          82       82              
  Lines        5556     5556              
==========================================
+ Hits         4984     4994      +10     
+ Misses        572      562      -10     

Files with missing lines	Coverage Δ
llm_web_kit/model/lang_id.py	65.35% <100.00%> (-0.04%)	⬇️

... and 4 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.