setup-isolated-setup-doctor

Runtime routing (run before the Claude-specific probes)

Use the operator's explicitly requested runtime when supplied; otherwise use the active session's runtime. An installed executable or configuration directory alone does not select a runtime. For the routing below, treat that selection as the active harness.

When the active harness is Codex, first require the static verification in docs/adapters/codex.md, then run the shared live environment probes inside the active Codex sandbox. Attribute failures separately to native sandbox/network denial, approval policy, or the POSIX agent-iso layer. Do not prescribe a .claude settings change for a Codex failure. Then stop before the Claude-specific branch below.