chore[dependency]:취약점이 있는 의존성 보완 및 MySql 의존성 추가

Author: asowjdan

backend/build.gradle

@@ -25,22 +25,34 @@ repositories {
 }
 
 dependencies {
+    // Spring Boot Starters (핵심 기능)
     implementation 'org.springframework.boot:spring-boot-starter-cache'
     implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
     implementation 'org.springframework.boot:spring-boot-starter-security'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
     implementation 'org.springframework.boot:spring-boot-starter-web'
-    implementation("org.springdoc:springdoc-openapi-starter-webmvc-ui:2.8.9")
+
+    // API Documentation (문서화)
+    implementation 'org.apache.commons:commons-lang3:3.18.0'
+    implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.8.9'
+
+    // Database (데이터베이스)
+    runtimeOnly 'com.h2database:h2'
+    runtimeOnly 'com.mysql:mysql-connector-j'
+
+    // Development Tools (개발 도구)
     compileOnly 'org.projectlombok:lombok'
     developmentOnly 'org.springframework.boot:spring-boot-devtools'
-    runtimeOnly 'com.h2database:h2'
-    runtimeOnly 'org.postgresql:postgresql'
+
+    // Annotation Processing (어노테이션 처리)
     annotationProcessor 'org.projectlombok:lombok'
+
+    // Testing (테스트)
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
     testImplementation 'org.springframework.security:spring-security-test'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
 }
 
 tasks.named('test') {
     useJUnitPlatform()
-}
+}