* fix(anthropic): fix streaming + response_format + tools bug
- Fix _handle_json_mode_chunk to only convert response_format tools to content
- Regular user tools now remain as proper tool_calls in streaming mode
- Add comprehensive test for the fix
- Resolves issue where all tools were incorrectly converted to content chunks
Before: All tools converted to content with different indices
After: Only response_format tool converted, regular tools remain as tool_calls
* fix(anthropic): improve streaming + response_format + tools handling
* fix: lint error (too many statements)
* fix(anthropic): correct finish_reason for streaming response_format tools
