feat: add core schema and status enums

backend/src/test/java/com/linhelp/common/enums/StatusTransitionTests.java

@@ -0,0 +1,25 @@
+package com.linhelp.common.enums;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StatusTransitionTests {
+
+    @Test
+    void goodsOrderCanMoveFromPendingConfirmToPreparing() {
+        assertThat(GoodsOrderStatus.PENDING_CONFIRM.canMoveTo(GoodsOrderStatus.PREPARING)).isTrue();
+    }
+
+    @Test
+    void goodsOrderCannotMoveFromCompletedToDelivering() {
+        assertThat(GoodsOrderStatus.COMPLETED.canMoveTo(GoodsOrderStatus.DELIVERING)).isFalse();
+    }
+
+    @Test
+    void expressOrderCanMoveThroughPickupFlow() {
+        assertThat(ExpressOrderStatus.PENDING_CONFIRM.canMoveTo(ExpressOrderStatus.PENDING_PICKUP)).isTrue();
+        assertThat(ExpressOrderStatus.PENDING_PICKUP.canMoveTo(ExpressOrderStatus.PICKING_UP)).isTrue();
+        assertThat(ExpressOrderStatus.PICKING_UP.canMoveTo(ExpressOrderStatus.DELIVERING)).isTrue();
+    }
+}