Wraps surfaceError for cases where the caller doesn't know the error
shape upfront (typical useMutation.onError and catch (err: unknown)
sites). When err is not an AppError, fabricates a synthetic
Internal-shaped notification so the user still sees something rather
than silence.
Surface an arbitrary unknown error value.
Wraps
surfaceErrorfor cases where the caller doesn't know the error shape upfront (typicaluseMutation.onErrorandcatch (err: unknown)sites). Whenerris not anAppError, fabricates a syntheticInternal-shaped notification so the user still sees something rather than silence.