feat(wcs): add shared domain contracts

ruoyi-wcs/src/main/java/com/ruoyi/wcs/domain/shared/DomainEvent.java

@@ -0,0 +1,51 @@
+package com.ruoyi.wcs.domain.shared;
+
+import java.time.Instant;
+import java.util.Objects;
+
+public final class DomainEvent {
+    private final String eventId;
+    private final String aggregateId;
+    private final long sequence;
+    private final Instant occurredAt;
+    private final String type;
+
+    public DomainEvent(String eventId, String aggregateId, long sequence,
+                       Instant occurredAt, String type) {
+        this.eventId = requireText(eventId, "eventId");
+        this.aggregateId = requireText(aggregateId, "aggregateId");
+        if (sequence < 1L) {
+            throw new IllegalArgumentException("sequence must be positive");
+        }
+        this.sequence = sequence;
+        this.occurredAt = Objects.requireNonNull(occurredAt, "occurredAt");
+        this.type = requireText(type, "type");
+    }
+
+    public String getEventId() {
+        return eventId;
+    }
+
+    public String getAggregateId() {
+        return aggregateId;
+    }
+
+    public long getSequence() {
+        return sequence;
+    }
+
+    public Instant getOccurredAt() {
+        return occurredAt;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    private static String requireText(String value, String field) {
+        if (value == null || value.trim().isEmpty()) {
+            throw new IllegalArgumentException(field + " must not be blank");
+        }
+        return value;
+    }
+}

ruoyi-wcs/src/main/java/com/ruoyi/wcs/domain/shared/DomainRuleViolation.java

@@ -0,0 +1,7 @@
+package com.ruoyi.wcs.domain.shared;
+
+public final class DomainRuleViolation extends RuntimeException {
+    public DomainRuleViolation(String message) {
+        super(message);
+    }
+}

ruoyi-wcs/src/main/java/com/ruoyi/wcs/domain/shared/IdGenerator.java

@@ -0,0 +1,5 @@
+package com.ruoyi.wcs.domain.shared;
+
+public interface IdGenerator {
+    String nextId();
+}

ruoyi-wcs/src/main/java/com/ruoyi/wcs/domain/shared/WcsClock.java

@@ -0,0 +1,7 @@
+package com.ruoyi.wcs.domain.shared;
+
+import java.time.Instant;
+
+public interface WcsClock {
+    Instant now();
+}

ruoyi-wcs/src/test/java/com/ruoyi/wcs/domain/shared/SharedContractsTest.java

@@ -0,0 +1,36 @@
+package com.ruoyi.wcs.domain.shared;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.Instant;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class SharedContractsTest {
+
+    @Test
+    void rejectsBlankEventIdentity() {
+        assertThrows(IllegalArgumentException.class, () ->
+                new DomainEvent("", "ORDER-1", 1L, Instant.EPOCH, "OrderAccepted"));
+    }
+
+    @Test
+    void rejectsInvalidEventSequence() {
+        assertThrows(IllegalArgumentException.class, () ->
+                new DomainEvent("E-1", "ORDER-1", 0L, Instant.EPOCH, "OrderAccepted"));
+    }
+
+    @Test
+    void exposesDeterministicEventFields() {
+        Instant occurredAt = Instant.parse("2026-08-04T00:00:00Z");
+        DomainEvent event = new DomainEvent("E-1", "ORDER-1", 2L,
+                occurredAt, "OrderPlanned");
+
+        assertEquals("E-1", event.getEventId());
+        assertEquals("ORDER-1", event.getAggregateId());
+        assertEquals(2L, event.getSequence());
+        assertEquals(occurredAt, event.getOccurredAt());
+        assertEquals("OrderPlanned", event.getType());
+    }
+}