Update project functionality and configuration

potal/agent-test-backend/build.gradle

@@ -0,0 +1,27 @@
+plugins {
+    id 'java'
+    id 'org.springframework.boot' version '3.5.11'
+    id 'io.spring.dependency-management' version '1.1.7'
+}
+
+group = 'com.example'
+version = '0.1.0'
+description = 'agent-test-backend'
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+dependencies {
+    implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.springframework.boot:spring-boot-starter-validation'
+
+    testImplementation 'org.springframework.boot:spring-boot-starter-test'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+}
+
+tasks.named('test') {
+    useJUnitPlatform()
+}