[Yash-Petkar]

Summary

• Handle NaN before converting the number to an integer in cJSON_SetNumberHelper().
• Set valueint to 0 for NaN while preserving the original NaN in valuedouble.
• Add a regression test covering both values.

This preserves the existing integer-boundary and infinity handling.

Testing

• CMake configuration and build completed successfully with MSVC.
• CTest: all 19 tests passed.
• git diff --check passed.

Related issue

Addresses the NaN-to-integer conversion issue reported in #1100. Related: #805 and #1000.