Replace the bash pi-agent script with typed Haskell commands in agentd. Agentd becomes the single CLI and daemon for managing Pi agents, delegating process lifecycle to systemd.
Design doc: ~/agentd-unification-design.md
Key principles:
Subtasks: t-740 through t-746
Completed unification sequence t-740..t-746 and moved all to Review. Key outcomes: new agentd agent CLI and persistent control-plane, daemon routes switched to create/list/status/send/stop/delete via systemd delegation, agentd service manifest now uses /home/ben/.local/share/omni/agentd.db and /home/ben/.local/state/agentd, client/web switched to remove semantics, Ava spawn payload now uses cwd and orchestrator cleanup now calls DELETE /agents/:id (with stop fallback). Verified with lint/typecheck/bild and live HTTP smoke tests against system service on :8400.