Roadmap: add a Claude Code provider adapter without changing the runtime contract

## Goal

Publish a Claude Code adapter that reuses the provider-neutral CodeCanopy node, dependency, safety, and proof-receipt contracts.

## Scope

- Map lead, expert, worker, and reviewer roles to configurable Claude models and effort.
- Map bounded nesting, concurrency, turn limits, permissions, and worktree isolation to documented Claude Code capabilities.
- Preserve the same Leaf Test, path ownership, parent integration, and authority rules.
- Package Claude-specific skills or agents separately when the host format requires it.
- Add one nested scenario and one atomic scenario.

## Non-goals

- Do not make experimental Agent Teams the foundation.
- Do not silently translate unsupported settings.
- Do not claim parity before the adapter scenarios pass.
- Do not add a daemon, database, or scheduler.

## Acceptance

Unsupported mappings are reported visibly, host policy remains authoritative, and the same normalized result can be consumed by the root regardless of provider.