How

Explore the codebase to answer "how does X work?" questions. Produce clear architectural explanations at the level of a senior engineer onboarding onto a subsystem — enough to build a working mental model, not so much that it reads like annotated source code.

Two modes:

1. Explain (default) — explore the codebase and produce a clear explanation
2. Critique — explain first, then spawn multiple models to independently identify architectural issues

Explain Mode

Step 1 — Understand the Question and Assess Complexity

Parse what the user is asking about. They might say:

• "How does message virtualization work?" — a subsystem
• "How do we handle billing for on-demand usage?" — a feature flow
• "How is the auth service structured?" — an architectural overview
• "Walk me through what happens when a user sends a message" — a runtime trace