Add compatibility shims at top-level to re-export SYS modules (pipeline/result_table/metadata/models/rich_display)

metadata.py

@@ -0,0 +1,11 @@
+"""Backwards-compatibility shim for top-level `metadata` module.
+
+Moved into `SYS.metadata` — keep the old import path working for tests
+and third-party code.
+"""
+
+from importlib import import_module
+import sys
+
+_real = import_module("SYS.metadata")
+sys.modules[__name__] = _real