How Explore the codebase to answer "how does X work?" questions. Produce 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. Every spawn is a Task subagent with and . Explorers use the line in the rule (default ), and every explainer uses the line (default ). Set to that line's value, or to the default if the rule or the line is missing. Leave unset when the value is or . If the Task tool rejects a slug, use the default and say so. If it rejects the default, use…