v2.64.2 — board agent: visible Run failures

Patch: the Agent runner 'Run' no longer fails silently.

Root cause of "agent runner doesn't start": a board process started before the agent endpoints existed (stale process) — the static HTML serves fresh from disk (so you see the panel), but /api/agent/run 404s on the old server, and the error-swallowing api() helper hid it (it set 'running…' but nothing happened).

Fix: agentRun/agentStop use a direct fetch that surfaces network/404 errors, with a clear hint — restart the board (great-cto board / node packages/board/server.mjs) to load /api/agent/*.

If you hit this: just restart your board.