Add household and membership domain with role-based APIs

Introduced `Household` and `HouseholdMember` entities, services, and repositories, enabling role-based access (`OWNER` and `MEMBER`). Added REST APIs for household creation, member management, and listing. Configured Flyway migrations, updated tests, and included IntelliJ HTTP client script for API testing. Updated `README.md` with feature details, usage instructions, and architecture overview.

build.gradle

@@ -11,22 +11,38 @@ java { toolchain { languageVersion = JavaLanguageVersion.of(21) } }
 
 repositories { mavenCentral() }
 
+ext['flyway.version'] = '10.17.3'  // managed override
+
 dependencies {
-    implementation 'org.springframework.boot:spring-boot-starter-security'
-    implementation 'org.springframework.boot:spring-boot-starter-oauth2-resource-server'
-    implementation 'org.springframework.security:spring-security-oauth2-jose'
+    // --- Spring starters ---
     implementation 'org.springframework.boot:spring-boot-starter-web'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
+    implementation 'org.springframework.boot:spring-boot-starter-security'
+    implementation 'org.springframework.boot:spring-boot-starter-oauth2-resource-server'
+    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
     implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.6.0'
-    testImplementation 'org.springframework.security:spring-security-test'
 
-    runtimeOnly 'org.postgresql:postgresql'
+    // Core Flyway + Postgres driver plugin
     implementation 'org.flywaydb:flyway-core'
+    implementation 'org.flywaydb:flyway-database-postgresql'
 
+    // DB driver
+    runtimeOnly 'org.postgresql:postgresql:42.7.4'
+
+    // --- Lombok (used in services/guards) ---
+    compileOnly 'org.projectlombok:lombok:1.18.32'
+    annotationProcessor 'org.projectlombok:lombok:1.18.32'
+    testCompileOnly 'org.projectlombok:lombok:1.18.32'
+    testAnnotationProcessor 'org.projectlombok:lombok:1.18.32'
+
+    // --- Tests ---
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
     testImplementation 'org.springframework.security:spring-security-test'
+    testImplementation 'com.jayway.jsonpath:json-path:2.9.0'
+    testRuntimeOnly 'com.h2database:h2:2.2.224' // for application-test.yml profile
 }
 
+
 test {
     useJUnitPlatform()
     finalizedBy jacocoTestReport