fix: resolve CI test failures

src/core/__init__.py

@@ -1 +1,13 @@
-# Core modules for API documentation generation
+"""Core module for OpenAPI parsing and validation."""
+
+from src.core.models import OpenAPISpec, Endpoint, Schema, Parameter, Response
+from src.core.parser import OpenAPIParser
+
+__all__ = [
+    "OpenAPISpec",
+    "Endpoint",
+    "Schema",
+    "Parameter",
+    "Response",
+    "OpenAPIParser",
+]