Align portability.md with the handoff refactor — every command and
subagent is now a thin wrapper whose substance lives in guides/, with
no self-contained inline exceptions.
Document the portability protocol (vendor-neutral knowledge, vendor-named
symlinks) and a Claude subagents reference handbook, and link the
portability protocol from the retrofit playbook.
Plain-prose guides that the Claude subagent wrappers read and follow:
evaluator, exerciser, researcher, reviewer, security-auditor,
start9-spec-checker, and the full-eval orchestration guide.
Move the Claude command/agent files from claude/ to adapters/claude/ to
match the adapters/<vendor>/ layout, and add the subagent definitions
(evaluator, exerciser, researcher, reviewer, security-auditor,
start9-spec-checker) plus the full-eval command wrapper.
Move the handoff checklist body into guides/handoff.md as plain prose,
and replace the Claude command with a thin wrapper that reads the guide,
matching the full-eval pattern.