feat(engine): scaffold runtime skeleton

Data/Engine/__init__.py

@@ -0,0 +1,11 @@
+"""Borealis Engine runtime package.
+
+This package houses the next-generation server runtime that will gradually
+replace :mod:`Data.Server.server`. Stage 1 focuses on providing a skeleton
+application factory and service placeholders so later stages can port
+features incrementally.
+"""
+
+from .server import create_app, EngineContext  # re-export for convenience
+
+__all__ = ["create_app", "EngineContext"]