Set up the loop foundation

Before building the agent chain, you need to set up the loop infrastructure that enables retry logic. This involves two nodes:

1. Init Variables — An Edit Fields (Set) node that initializes retry_count (starts at 0) and feedback_context (starts empty)
2. Loop Merge — A Merge node that combines the initial data with feedback from retry attempts

This pattern is how n8n handles loops: instead of a traditional "while" loop, you use a Merge node to combine the starting point with data that loops back.