feat(sprint-5): Phase 1 — Docker Compose full stack, CORS, Next.js upgrade

- Dockerfile.backend: multi-stage Java 21 build (eclipse-temurin)
- docker-compose.yml: PostgreSQL 16 + backend + frontend with health checks
- SecurityConfig: CORS for localhost:3000 frontend origin
- application-docker.properties: Docker profile with env vars
- Spring Boot Actuator health endpoint enabled
- Next.js upgraded 15.2.8 → 15.5.18 (security fixes)

cannamanage-api/pom.xml

@@ -118,6 +118,11 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-mail</artifactId>
         </dependency>
+        <!-- Actuator (health endpoint for Docker) -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

cannamanage-api/src/main/java/de/cannamanage/api/security/SecurityConfig.java

@@ -1,6 +1,7 @@
 package de.cannamanage.api.security;
 
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.annotation.Order;
@@ -13,8 +14,12 @@ import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
 import org.springframework.security.web.csrf.CookieCsrfTokenRepository;
+import org.springframework.web.cors.CorsConfiguration;
+import org.springframework.web.cors.CorsConfigurationSource;
+import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
 
 import jakarta.servlet.http.HttpServletResponse;
+import java.util.List;
 
 /**
  * Security configuration — Sprint 3: API + Staff portal with JWT + Member portal with sessions.
@@ -38,6 +43,7 @@ public class SecurityConfig {
     public SecurityFilterChain apiSecurityFilterChain(HttpSecurity http) throws Exception {
         http
                 .securityMatcher("/api/**")
+                .cors(cors -> cors.configurationSource(corsConfigurationSource()))
                 .csrf(csrf -> csrf.disable())
                 .sessionManagement(session -> session
                         .sessionCreationPolicy(SessionCreationPolicy.STATELESS))
@@ -116,4 +122,21 @@ public class SecurityConfig {
     public PasswordEncoder passwordEncoder() {
         return new BCryptPasswordEncoder();
     }
+
+    @Bean
+    public CorsConfigurationSource corsConfigurationSource() {
+        CorsConfiguration config = new CorsConfiguration();
+        config.setAllowedOrigins(List.of(
+                "http://localhost:3000",
+                "http://frontend:3000"
+        ));
+        config.setAllowedMethods(List.of("GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS"));
+        config.setAllowedHeaders(List.of("*"));
+        config.setAllowCredentials(true);
+        config.setMaxAge(3600L);
+
+        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
+        source.registerCorsConfiguration("/api/**", config);
+        return source;
+    }
 }

cannamanage-api/src/main/resources/application-docker.properties

@@ -0,0 +1,19 @@
+# Docker profile — used when running in Docker Compose
+spring.datasource.url=${SPRING_DATASOURCE_URL}
+spring.datasource.username=${SPRING_DATASOURCE_USERNAME}
+spring.datasource.password=${SPRING_DATASOURCE_PASSWORD}
+
+# Enable Flyway for container startup (fresh DB)
+spring.flyway.enabled=true
+spring.jpa.hibernate.ddl-auto=validate
+
+# JWT secret from environment
+cannamanage.security.jwt.secret=${CANNAMANAGE_SECURITY_JWT_SECRET}
+
+# Actuator
+management.endpoints.web.exposure.include=health
+management.endpoint.health.show-details=never
+
+# Disable mail in Docker (no SMTP container)
+spring.mail.host=localhost
+spring.mail.port=1025

cannamanage-api/src/main/resources/application.properties

@@ -31,6 +31,10 @@ spring.mail.from=${MAIL_FROM:noreply@cannamanage.de}
 # App base URL (for invite links)
 app.base-url=${APP_BASE_URL:http://localhost:8080}
 
+# Actuator
+management.endpoints.web.exposure.include=health
+management.endpoint.health.show-details=never
+
 # Session configuration (member portal)
 server.servlet.session.timeout=30m
 server.servlet.session.cookie.same-site=strict