Add NHN Cloud API integration with async task support

- NHN Cloud API packages: token, vpc, compute, nks, storage
- REST API endpoints with Swagger documentation
- Async task processing for long-running operations
- CORS configuration for frontend integration
- Enhanced logging for debugging API calls

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

nhn/authentication.py

@@ -0,0 +1,28 @@
+from rest_framework_simplejwt.authentication import JWTAuthentication
+from rest_framework_simplejwt.exceptions import InvalidToken
+
+
+class StatelessUser:
+    """
+    Stateless user class for JWT authentication.
+    Does not require database User model.
+    """
+
+    def __init__(self, username):
+        self.username = username
+        self.is_authenticated = True
+
+    def __str__(self):
+        return self.username
+
+
+class StatelessJWTAuthentication(JWTAuthentication):
+    """
+    Custom JWT authentication that extracts user from token's 'name' claim.
+    """
+
+    def get_user(self, validated_token):
+        name = validated_token.get("name")
+        if not name:
+            raise InvalidToken("Token does not contain 'name' claim.")
+        return StatelessUser(username=name)