AgentBridge's start/restart actions only ever checked an explicit apiKey
request field (never sent by the UI) and the ROUTER_API_KEY process env
var (unset unless manually exported), so startMitm() always spawned
server.cjs with an empty ROUTER_API_KEY and it hard-exited with
"no API key was provided". resolveRouterApiKey() now falls back to
pickApiKeyForInternalUse(), the same DB-backed selector already used by
the combo-health-check / cloud-sync-verify internal probes.
78f05fc639