feat(community): add findAllWithDetails query to MembershipRepository

Add @Query with JOIN FETCH on meteringPoint and energyCommunity, no WHERE clause
to return all memberships regardless of status. Includes reflection-based unit test
verifying method existence and annotation correctness.

eeg_backend/src/main/java/at/mueller/eeg/backend/community/repository/MembershipRepository.java

@@ -37,6 +37,9 @@ public interface MembershipRepository extends JpaRepository<Membership, UUID> {
     @Query("SELECT m FROM Membership m JOIN FETCH m.meteringPoint mp JOIN FETCH m.energyCommunity ec WHERE m.status = 'PENDING'")
     List<Membership> findPendingWithDetails();
 
+    @Query("SELECT m FROM Membership m JOIN FETCH m.meteringPoint mp JOIN FETCH m.energyCommunity ec")
+    List<Membership> findAllWithDetails();
+
     @Query("SELECT mp.userId FROM Membership m JOIN m.meteringPoint mp WHERE m.energyCommunity.id = :communityId AND m.status != 'INACTIVE'")
     List<UUID> findActiveMemberUserIdsByCommunityId(@Param("communityId") UUID communityId);
 

eeg_backend/src/test/java/at/mueller/eeg/backend/community/repository/MembershipRepositoryTest.java

@@ -0,0 +1,41 @@
+package at.mueller.eeg.backend.community.repository;
+
+import at.mueller.eeg.backend.community.domain.Membership;
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Method;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MembershipRepositoryTest {
+
+    @Test
+    void findAllWithDetails_methodExists() throws NoSuchMethodException {
+        Method method = MembershipRepository.class.getMethod("findAllWithDetails");
+        assertNotNull(method);
+        assertEquals(List.class, method.getReturnType());
+    }
+
+    @Test
+    void findAllWithDetails_hasQueryAnnotation() {
+        Method method = null;
+        try {
+            method = MembershipRepository.class.getMethod("findAllWithDetails");
+        } catch (NoSuchMethodException e) {
+            fail("findAllWithDetails method not found on MembershipRepository");
+        }
+
+        org.springframework.data.jpa.repository.Query queryAnnotation =
+                method.getAnnotation(org.springframework.data.jpa.repository.Query.class);
+        assertNotNull(queryAnnotation, "findAllWithDetails should have @Query annotation");
+
+        String queryValue = queryAnnotation.value();
+        assertTrue(queryValue.contains("JOIN FETCH m.meteringPoint"),
+                "Query should JOIN FETCH meteringPoint");
+        assertTrue(queryValue.contains("JOIN FETCH m.energyCommunity"),
+                "Query should JOIN FETCH energyCommunity");
+        assertFalse(queryValue.contains("WHERE"),
+                "Query should not have WHERE clause (returns all statuses)");
+    }
+}