I Built a RAG App, Then Asked It What Car I Like. It Didn't Know.

TL;DR: Phase 1 of a from-scratch RAG app — Spring AI, pgvector, local Ollama — ends with a working pipeline and two failures that look identical from the outside but have nothing to do with each other. One was a chunking bug. The other was a 3B model running out of brain. Here's how I told them apar