[router] add step3 tool parser (#9695)

Co-authored-by: Chang Su <chang.s.su@oracle.com>

sgl-router/src/tool_parser/parsers/mod.rs

@@ -9,12 +9,15 @@ pub mod llama_parser;
 pub mod mistral_parser;
 pub mod pythonic_parser;
 pub mod qwen_parser;
+pub mod step3_parser;
 
 // Re-export parser types for convenience
 pub use deepseek_parser::DeepSeekParser;
 
 pub use json_parser::JsonParser;
+
 pub use llama_parser::LlamaParser;
 pub use mistral_parser::MistralParser;
 pub use pythonic_parser::PythonicParser;
 pub use qwen_parser::QwenParser;
+pub use step3_parser::Step3Parser;