Simplify Router arguments passing and build it in docker image (#9964)

sgl-router/py_src/sglang_router/__init__.py

@@ -1,7 +1,3 @@
-# a lightweihgt wrapper on router with argument type and comments
-# no wrapper on policy type => direct export
-from sglang_router.router import Router
 from sglang_router.version import __version__
-from sglang_router_rs import PolicyType
 
-__all__ = ["Router", "PolicyType", "__version__"]
+__all__ = ["__version__"]