fix: add import path support for python sources

examples/python_source_ops.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+from wf_authoring import node
+
+
+class EchoInput(BaseModel):
+    text: str
+
+
+class EchoOutput(BaseModel):
+    echoed: str
+
+
+@node(name="echo")
+def echo(payload: EchoInput) -> EchoOutput:
+    """Return the submitted text through a project-local Python source."""
+    return EchoOutput(echoed=payload.text)
+
+
+@node(name="authoring.upper")
+def upper(payload: EchoInput) -> EchoOutput:
+    """Upper-case text while exercising authoring-name qualification."""
+    return EchoOutput(echoed=payload.text.upper())
+
+
+registry = [echo, upper]