feat: refactor Chain module

agents-flex-core/src/main/java/com/agentsflex/chain/Chain.java

@@ -19,10 +19,22 @@ import java.io.Serializable;
 
 public class Chain implements Serializable {
 
-    private String id;
-    private ChainContext context;
-    private Invoker[] invokers;
-    private int index = 0;
+    protected String id;
+    protected ChainContext context;
+    protected Invoker[] invokers;
+    protected int index = 0;
+
+    public Chain(Invoker[] invokers) {
+        this.invokers = invokers;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
 
     public ChainContext getContext() {
         return context;
@@ -32,6 +44,22 @@ public class Chain implements Serializable {
         this.context = context;
     }
 
+    public Invoker[] getInvokers() {
+        return invokers;
+    }
+
+    public void setInvokers(Invoker[] invokers) {
+        this.invokers = invokers;
+    }
+
+    public int getIndex() {
+        return index;
+    }
+
+    public void setIndex(int index) {
+        this.index = index;
+    }
+
     public void start() {
         doComplete();
     }

agents-flex-core/src/main/java/com/agentsflex/chain/ParallelChain.java

@@ -16,6 +16,10 @@
 package com.agentsflex.chain;
 
 public class ParallelChain extends Chain implements Invoker{
+    public ParallelChain(Invoker[] invokers) {
+        super(invokers);
+    }
+
     @Override
     public Chain getChain() {
         return null;

agents-flex-core/src/main/java/com/agentsflex/chain/SequentialChain.java

@@ -16,6 +16,10 @@
 package com.agentsflex.chain;
 
 public class SequentialChain extends Chain implements Invoker {
+    public SequentialChain(Invoker[] invokers) {
+        super(invokers);
+    }
+
     @Override
     public Chain getChain() {
         return null;