Registers JsonNullableModule globally so JsonNullable<String> in JourneyItemUpdateDTO can distinguish absent (unchanged) from explicit null (clear field) on PATCH operations. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Registers JsonNullableModule globally so JsonNullable<String> in JourneyItemUpdateDTO can distinguish absent (unchanged) from explicit null (clear field) on PATCH operations. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>