refactor: convert SubagentSelectedData to a record for improved data handling

Author: brunoborges

src/main/java/com/github/copilot/sdk/events/SubagentSelectedEvent.java

@@ -32,39 +32,13 @@ public void setData(SubagentSelectedData data) {
     }
 
     @JsonIgnoreProperties(ignoreUnknown = true)
-    public static class SubagentSelectedData {
+    public record SubagentSelectedData(@JsonProperty("agentName") String agentName,
+            @JsonProperty("agentDisplayName") String agentDisplayName, @JsonProperty("tools") String[] tools) {
 
-        @JsonProperty("agentName")
-        private String agentName;
-
-        @JsonProperty("agentDisplayName")
-        private String agentDisplayName;
-
-        @JsonProperty("tools")
-        private String[] tools;
-
-        public String getAgentName() {
-            return agentName;
-        }
-
-        public void setAgentName(String agentName) {
-            this.agentName = agentName;
-        }
-
-        public String getAgentDisplayName() {
-            return agentDisplayName;
-        }
-
-        public void setAgentDisplayName(String agentDisplayName) {
-            this.agentDisplayName = agentDisplayName;
-        }
-
-        public String[] getTools() {
+        /** Returns a defensive copy of the tools array. */
+        @Override
+        public String[] tools() {
             return tools == null ? null : tools.clone();
         }
-
-        public void setTools(String[] tools) {
-            this.tools = tools;
-        }
     }
 }

src/test/java/com/github/copilot/sdk/SessionEventParserTest.java

@@ -1736,13 +1736,13 @@ void testSubagentSelectedEventAllFields() throws Exception {
         var event = (SubagentSelectedEvent) parseJson(json);
         assertNotNull(event);
         var data = event.getData();
-        assertEquals("best-agent", data.getAgentName());
-        assertEquals("Best Agent", data.getAgentDisplayName());
-        assertNotNull(data.getTools());
-        assertEquals(3, data.getTools().length);
-        assertEquals("read", data.getTools()[0]);
-        assertEquals("write", data.getTools()[1]);
-        assertEquals("search", data.getTools()[2]);
+        assertEquals("best-agent", data.agentName());
+        assertEquals("Best Agent", data.agentDisplayName());
+        assertNotNull(data.tools());
+        assertEquals(3, data.tools().length);
+        assertEquals("read", data.tools()[0]);
+        assertEquals("write", data.tools()[1]);
+        assertEquals("search", data.tools()[2]);
     }
 
     // =========================================================================