fix(book): add @NotNull and @min(0) validation to availableCopies in

BookCreateDTO

availableCopies previously accepted null values and negative numbers
without any validation error. Added @NotNull and @min(0) to enforce
that the field is always provided and non-negative on book creation.

Author: erichiroshi

readme_pdf.md

@@ -1,3 +1,6 @@
+> Este documento é a versão técnica da documentação do projeto,
+> utilizada para geração do PDF via CI.
+
 # Library API — Spring Boot 4 + JWT + Docker + Observability
 
 Backend production-ready projetado com foco em previsibilidade, observabilidade e isolamento de responsabilidades.

src/main/java/com/example/library/book/dto/BookCreateDTO.java

@@ -2,6 +2,7 @@
 
 import java.util.Set;
 
+import jakarta.validation.constraints.Min;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.NotEmpty;
 import jakarta.validation.constraints.NotNull;
@@ -10,6 +11,7 @@
 
 @Builder
 public record BookCreateDTO(
+		
 		Long id,
 
 		@NotBlank
@@ -20,6 +22,9 @@ public record BookCreateDTO(
 
 	    @NotNull
 		Integer publicationYear, 
+		
+		@NotNull
+        @Min(value = 0, message = "Available copies must be zero or greater")
 		Integer availableCopies,
 
 		@NotNull

src/main/resources/application.yml

@@ -14,7 +14,7 @@ spring:
     default-property-inclusion: non_null
 
   profiles:
-    active: ${SPRING_PROFILES_ACTIVE:prod}
+    active: ${SPRING_PROFILES_ACTIVE:dev}
 
   servlet:
     multipart: