Lightweight alternative to /gsd-map-codebase that spawns a single
mapper agent for one focus area instead of four parallel agents.
Supports --focus flag with 5 options: tech, arch, quality, concerns,
and tech+arch (default). Checks for existing documents and prompts
before overwriting.
Closes#1733
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
