Remove generated files and clean repository

Day 7: refusal-hardened prompt (7/7), strict citations; faithful 0.89, correct 0.91

Day 5 ablations: hybrid recall@20=0.97, bge-reranker-base hurts MRR (0.71->0.63)

Baseline v0: recall@5 0.91, MRR 0.71, correct 0.89

Day 4: 42-question eval harness; fix max file size (routing.py was unindexed)

Day 2: AST-aware chunkers for code, docs, issues

Day 1: ingestion pipeline (code, docs, issues)