feat: add H2 database configuration and update MemoryItem to ignore embedding property in JSON serialization

Author: Aias00

example-usage/pom.xml

@@ -34,6 +34,12 @@
             <artifactId>mem4j-spring-boot-starter</artifactId>
             <version>0.1.0</version>
         </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>2.3.232</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
 
     <build>

example-usage/src/main/resources/application.yml

@@ -7,7 +7,11 @@ spring:
   ai:
     dashscope:
       api-key: ${DASHSCOPE_API_KEY:test-key}
-
+  datasource:
+    url: jdbc:h2:mem:memdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
+    driver-class-name: org.h2.Driver
+    username: sa
+    password: sa
 # Mem4j Configuration
 mem4j:
   # 使用内存向量存储（适合演示）

mem4j-core/src/main/java/com/github/mem4j/memory/MemoryItem.java

@@ -16,6 +16,7 @@
 
 package com.github.mem4j.memory;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import java.time.Instant;
@@ -55,7 +56,7 @@ public class MemoryItem {
 	@JsonProperty("updated_at")
 	private Instant updatedAt;
 
-	@JsonProperty("embedding")
+	@JsonIgnore
 	private Double[] embedding;
 
 	public MemoryItem() {