Improve Codebase Architecture

Explore a codebase like an AI would, surface architectural friction, discover opportunities for improving testability, and propose module-deepening refactor RFCs. Use the shared codebase-design vocabulary for modules, interfaces, depth, seams, adapters, leverage, and locality instead of redefining those terms here.

Owns: a bounded survey of one requested area, candidate comparison, and its refactor RFC. codebase-improver remains the separate human-gated full-repository workflow; this skill does not absorb its audit, implementation, or recursive deepening ownership.

Host portability

Without delegation authority, run exploration and design passes serially inline. Apply the operating defaults before selecting distinct workers. Do not claim inline passes are independent or parallel; report unavailable isolation when it is essential to the requested result.