Two root causes found via truss:
1. Bare command names (sudo, jexec) unresolved under daemon(8) PATH
→ fixed by resolve_program() in PR #131
2. Jail staging directory owned by root, unwritable by clawdie
→ fixed by chmod 777 <jail_root>/var/run/colibri-stage
Trace saved at /tmp/daemon.truss (1964 lines, successful spawn).