A Spaghetti Study Aid for Databricks and Spark That Somehow Became a Platform

I set out to write a few study notes for a Databricks interview and ended up with a four-part study platform: a notes vault, dual-track PySpark notebooks, a git-tracked HTML lesson runner, and a Copilot SDK chat app that answers questions grounded in the repo itself. Here is how the pieces fit, and where the spaghetti lives.