fix: error on unsupported Anthropic tool types instead of silently dropping them

[hustxiayang]

Description
When translating OpenAI tools to Anthropic, non-function tools (and function tools missing their definition) were silently skipped, so the model never received them and requests failed in confusing, hard-to-debug ways. This now returns a 400 (ErrInvalidRequestBody) with a clear message, matching the existing fail-closed behavior of the Gemini translator

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.03%. Comparing base (b80bc3e) to head (e75b751).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2467   +/-   ##
=======================================
  Coverage   85.03%   85.03%           
=======================================
  Files         159      159           
  Lines       22634    22638    +4     
=======================================
+ Hits        19247    19251    +4     
  Misses       2219     2219           
  Partials     1168     1168           

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[hustxiayang]

/retest