Systematic pre-implementation analysis that finds unknown unknowns — usability gaps, broken flows, state conflicts, concurrency hazards, error dead-ends, and edge cases BEFORE code is written. Fire-and-forget: runs all phases autonomously and delivers a severity-ordered report. Works across stacks — frontend, backend, CLI, mobile, APIs. Use this skill when: (1) before implementing any feature that changes existing behavior, (2) before adding async/background processing to what was synchronous, (3) when a feature touches shared state (global stores, caches, databases, queues), (4) when a feature has multiple entry points or triggers, (5) when moving functionality between surfaces or layers, (6) when the user asks to 'think through' or 'analyze' a feature before building it, (7) when reviewing a plan for hidden failure modes. Triggers on: 'analyze this feature', 'think through the flow', 'what could go wrong', 'check for edge cases', 'will this break anything', 'find problems with this', 'unknown unknowns', flow analysis, impact analysis, pre-implementation review.