blast-radius

Map the full blast radius of a code change before making it — every breaking reference, transitive (ripple) caller, affected test, and historically co-changing file — using the `br` CLI (LSP-backed, cross-language impact analysis). Use this whenever the user is about to rename, change the signature of, or remove a function, method, type, API endpoint, database column, or config/env key, or asks "what breaks if I change X", "what depends on this", "what calls this", "impact analysis", "is this safe to change/refactor", or "check the blast radius" — even if they don't say "blast radius" explicitly. Especially reach for it before refactoring shared code.