test: 修复测试并验证 Milvus 连接

- 修复 DocumentChunkServiceTest：getStartIndex/getEndIndex → getStartOffset/getEndOffset
- 新增 SimpleMilvusTest：验证 Milvus 集群连接状态
- Milvus 状态：✓ 正常运行（Status Code: 0）

测试结果：
- SimpleMilvusTest: 1/1 通过
- Milvus 集群可用，可以继续实施 Task 5.3-5.7

Host: in03-4a578da0f27ce9d.serverless.aws-eu-central-1.cloud.zilliz.com
Port: 443 (Zilliz Cloud Serverless)

src/test/java/com/superbiz/agent/service/DocumentChunkServiceTest.java

@@ -218,10 +218,10 @@ class DocumentChunkServiceTest {
             List<DocumentChunk> chunks = service.chunkDocument(content, "/test/index.md");
 
             for (DocumentChunk c : chunks) {
-                assertTrue(c.getStartIndex() >= 0);
-                assertTrue(c.getEndIndex() > c.getStartIndex(),
-                    "endIndex(" + c.getEndIndex() + ") 应 > startIndex(" + c.getStartIndex() + ")");
-                assertTrue(c.getEndIndex() <= content.length());
+                assertTrue(c.getStartOffset() >= 0);
+                assertTrue(c.getEndOffset() > c.getStartOffset(),
+                    "endIndex(" + c.getEndOffset() + ") 应 > startIndex(" + c.getStartOffset() + ")");
+                assertTrue(c.getEndOffset() <= content.length());
             }
         }
     }
@@ -326,7 +326,7 @@ class DocumentChunkServiceTest {
             System.out.println("  长列表硬上限测试 — 实际分块数: " + chunks.size());
             for (DocumentChunk c : chunks) {
                 System.out.println("    Chunk #" + c.getChunkIndex() + ": " + c.getContent().length() + "字符 "
-                    + "| start=" + c.getStartIndex() + " end=" + c.getEndIndex()
+                    + "| start=" + c.getStartOffset() + " end=" + c.getEndOffset()
                     + " | preview=" + c.getContent().substring(0, Math.min(60, c.getContent().length())).replace("\n", "\\n"));
             }
 
@@ -486,7 +486,7 @@ class DocumentChunkServiceTest {
             for (DocumentChunk c : chunks) {
                 System.out.println("┌─ Chunk #" + c.getChunkIndex());
                 System.out.println("│  Title: " + (c.getTitle() != null ? c.getTitle() : "(无)"));
-                System.out.println("│  Range: [" + c.getStartIndex() + "→" + c.getEndIndex() + "] (" + c.getContent().length() + "字符)");
+                System.out.println("│  Range: [" + c.getStartOffset() + "→" + c.getEndOffset() + "] (" + c.getContent().length() + "字符)");
                 // 显示前150字符
                 String preview = c.getContent().length() > 120
                     ? c.getContent().substring(0, 120).replace("\n", "\\n") + "..."

src/test/java/com/superbiz/agent/service/SimpleMilvusTest.java

@@ -0,0 +1,62 @@
+package com.superbiz.agent.service;
+
+import io.milvus.client.MilvusServiceClient;
+import io.milvus.param.ConnectParam;
+import io.milvus.param.R;
+import io.milvus.param.collection.HasCollectionParam;
+import org.junit.jupiter.api.Test;
+
+/**
+ * 简单的 Milvus 连接测试
+ */
+public class SimpleMilvusTest {
+
+    @Test
+    public void testConnection() {
+        String host = "in03-4a578da0f27ce9d.serverless.aws-eu-central-1.cloud.zilliz.com";
+        int port = 443;
+        String token = "d246a77f43a109685596e3c68ecfd359e1cd8b29d35c41d708160f02b97ae623d2ab392738df740d0c77b58ca1bbadfa7c412140";
+
+        System.out.println("尝试连接 Milvus...");
+        System.out.println("Host: " + host);
+        System.out.println("Port: " + port);
+
+        try {
+            MilvusServiceClient client = new MilvusServiceClient(
+                ConnectParam.newBuilder()
+                    .withHost(host)
+                    .withPort(port)
+                    .withToken(token)
+                    .withSecure(true)
+                    .withConnectTimeout(10L, java.util.concurrent.TimeUnit.SECONDS)
+                    .build()
+            );
+
+            System.out.println("✓ 客户端创建成功");
+
+            // 测试连接：查询是否存在某个 collection
+            R<Boolean> response = client.hasCollection(
+                HasCollectionParam.newBuilder()
+                    .withCollectionName("test_collection")
+                    .build()
+            );
+
+            System.out.println("✓ 连接成功！");
+            System.out.println("Status Code: " + response.getStatus());
+
+            if (response.getStatus() == 0 || response.getStatus() == io.milvus.param.R.Status.Success.getCode()) {
+                System.out.println("✓ Milvus 集群状态：正常运行");
+            } else {
+                System.out.println("✗ 响应状态异常: " + response.getStatus());
+            }
+
+            client.close();
+            System.out.println("✓ 连接已关闭");
+
+        } catch (Exception e) {
+            System.err.println("✗ 连接失败：" + e.getMessage());
+            e.printStackTrace();
+            throw new RuntimeException("Milvus 连接失败", e);
+        }
+    }
+}