Scaffold Spring Boot 4.0.5 project with domain packages

Maven project with Java 21. Dependencies: web, data-jpa, security,
validation, flyway, postgresql, springdoc-openapi 3.0.2.
Package-by-domain structure: auth, household, recipe, planning,
shopping, pantry, admin, common. JPA open-in-view disabled,
Hibernate ddl-auto=validate (Flyway owns the schema).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/main/resources/application.yml

@@ -0,0 +1,23 @@
+spring:
+  application:
+    name: mealprep
+
+  datasource:
+    url: jdbc:postgresql://localhost:5432/mealprep
+    username: mealprep
+    password: mealprep
+
+  jpa:
+    open-in-view: false
+    hibernate:
+      ddl-auto: validate
+    properties:
+      hibernate:
+        dialect: org.hibernate.dialect.PostgreSQLDialect
+
+  flyway:
+    enabled: true
+    locations: classpath:db/migration
+
+server:
+  port: 8080