The mandatory first move on any brownfield task. Maps the existing codebase's structure, infers its conventions and architecture, locates seams, identifies risk areas and test-coverage gaps, and writes the persistent `.repo-intel/` artifact (architecture map, dependency graph, service map, ownership map, hotspot analysis) that every downstream skill consults. Incrementally updated rather than recomputed on each engagement. Brownfield-only (B-only) — does nothing on a greenfield empty repo. Use at the start of any work against an existing codebase, and on cadence as the codebase evolves.
