agents/ contained only README.md after the 2026-05-09 migration. The
roster information is more naturally located alongside the skills it
points into. skills/README.md is now the single index (skill table,
pipeline diagram, agent roster, discovery, conventions, how-to-add).
CLAUDE.md updated: code-layout entry consolidated, @-reference points
to skills/README.md.
ailang-implementer/-tester -> skills/implement/agents/
ailang-architect/-bencher/-docwriter -> skills/audit/agents/
ailang-debugger -> skills/debug/agents/
agents/ now contains only README.md (rewritten in next commit as
roster of skill-bound agents).