feat: add email verification

src/main/java/com/openisle/controller/HelloController.java

@@ -2,6 +2,7 @@ package com.openisle.controller;
 
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
+import java.util.Map;
 
 @RestController
 public class HelloController {
@@ -10,7 +11,7 @@ public class HelloController {
      *   -H "Authorization: Bearer <jwt-token>"
      */
     @GetMapping("/api/hello")
-    public String hello() {
-        return "Hello, Authenticated User";
+    public Map<String, String> hello() {
+        return Map.of("message", "Hello, Authenticated User");
     }
 }