Deep repository analysis to realign project plans with actual code reality. `/drift-detect` discovers drift between documented plans (CHANGELOG, ARCHITECTURE.md, design docs, README claims) and what the code actually does, then produces a prioritized reconstruction plan. Pure JavaScript collectors gather data fast (no LLM overhead) and a single Opus call performs the deep semantic analysis - 77% fewer tokens than multi-agent approaches. Tested on 1,000+ repositories. Outputs a ranked list of drift items with severity, evidence, and suggested resolution.