feat: add shared library as git submodule

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

path_setup.py

@@ -0,0 +1,7 @@
+import sys
+import os
+
+# Add the shared library submodule to the Python path
+_shared = os.path.join(os.path.dirname(os.path.abspath(__file__)), "shared_lib")
+if _shared not in sys.path:
+    sys.path.insert(0, _shared)