Update observer and sync defaults for this viewer.
Model Runtime
`auto` uses provider defaults for the selected runtime.
Run observer calls through local Claude runtime auth.
Auth Adapter
Choose how observer credentials are resolved.
Command stdout is used as the token when source is `command` (argv only; no shell).
Command format: JSON string array, e.g. `["iap-auth", "--audience", "gateway"]`.
Template variables: `${auth.token}`, `${auth.type}`, `${auth.source}`.
Environment variables override file settings.