chore: import upstream snapshot with attribution

flow.py

@@ -0,0 +1,33 @@
+from pocketflow import Flow
+# Import all node classes from nodes.py
+from nodes import (
+    FetchRepo,
+    IdentifyAbstractions,
+    AnalyzeRelationships,
+    OrderChapters,
+    WriteChapters,
+    CombineTutorial
+)
+
+def create_tutorial_flow():
+    """Creates and returns the codebase tutorial generation flow."""
+
+    # Instantiate nodes
+    fetch_repo = FetchRepo()
+    identify_abstractions = IdentifyAbstractions(max_retries=5, wait=20)
+    analyze_relationships = AnalyzeRelationships(max_retries=5, wait=20)
+    order_chapters = OrderChapters(max_retries=5, wait=20)
+    write_chapters = WriteChapters(max_retries=5, wait=20) # This is a BatchNode
+    combine_tutorial = CombineTutorial()
+
+    # Connect nodes in sequence based on the design
+    fetch_repo >> identify_abstractions
+    identify_abstractions >> analyze_relationships
+    analyze_relationships >> order_chapters
+    order_chapters >> write_chapters
+    write_chapters >> combine_tutorial
+
+    # Create the flow starting with FetchRepo
+    tutorial_flow = Flow(start=fetch_repo)
+
+    return tutorial_flow