Remove cached API responses from tracking

Phase 9 polish: structured output format, HTML UI components, citation highlighting

Phase 9: Gradio UI, critic debug panel, claim table, session sidebar, MD export

Phase 8: LangGraph state machine, full pipeline, retry loop, session loader

Phase 5: retriever agent, S2 keyword conversion, hybrid scoring, citation graph

Phase 3: retriever utils, hybrid scoring, DDG+S2 wrappers, disk cache

Phase 2: state schema, SQLite session memory, data dir