Fetch the account’s meters. One attempt: the caller always has a local
fallback, and in watch mode a previous answer, so a retry ladder would only
stall the frame it is drawn into.
The Go key: OCUSE_API_KEY, else OPENCODE_API_KEY, else the opencode-go
entry of opencode’s own auth file — the same credential /connect stores.
The bearer token, in opencode’s own order of precedence.