I spent two months building Vestibule, an open-source Python framework for the boring layer of RAG ingestion — stable document IDs, a state ledger, error classification, per-vertical governance. The parts every team struggles with once the demo works and production doesn't. Most of the code wasn't typed by me. Four AI agents did the work — one wrote designs, one reviewed them, one implemented, one reviewed the code — all through real GitHub pull requests, with me signing off at every gate. Th...