feat(devkitd): switch agent list and detail to daemon agent.list #411

Part of the devkitd agent migration (#406). agent.list RPC already exists — this is the client switchover.

Scope

agent list + agent detail → daemon path:

• DaemonClient.listAgents — verify payload carries sessionFilePath, pinned, status, lastActive (sweep already collects session_file)
• CLI: daemon-first with manager.listAgents fallback
• Confirm registry_overlays name/pin overlay covers all listed fields

Acceptance

• agent list/detail read from daemon when available
• Output shape/flags identical