Add StringToVector<std::string> overload for char*.

This overload allows `StringToVector` to accept a `char*` argument when parsing into a `std::vector<std::string>`, by converting the `char*` to `std::string` before processing.

PiperOrigin-RevId: 902611443
Change-Id: I2048918f915c1bac74522f368ea28f23ca9a6885

src/user/user_util.cc

@@ -1333,6 +1333,10 @@ template <typename T> std::vector<T> StringToVector(char* cs) {
   return v;
 }
 
+template<> MJAPI std::vector<std::string> StringToVector(char* cs) {
+  return StringToVector<std::string>(std::string(cs));
+}
+
 template<> MJAPI std::vector<std::string> StringToVector(const std::string& s) {
   std::vector<std::string> v;
   std::stringstream ss(s);

src/user/user_util.h

@@ -264,6 +264,7 @@ template<typename T> MJAPI std::string VectorToString(const std::vector<T>& v);
 // convert string to vector
 template<typename T> MJAPI std::vector<T> StringToVector(char *cs);
 template<typename T> MJAPI std::vector<T> StringToVector(const std::string& s);
+template<> MJAPI std::vector<std::string> StringToVector(char* cs);
 template<> MJAPI std::vector<std::string> StringToVector(const std::string& s);
 
 }  // namespace mujoco::user