The stack path in spec.yml is relative — both create_operation and
up_operation need cwd at the repo root for stack_is_external() to
resolve it. Move os.chdir(prev_cwd) to after up_operation completes
instead of between the two operations.
Reverts the SystemExit catch in call_stack_deploy_start — the root
cause was cwd, not the hook.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
61afeb255c