Deadline applied independently to every selected indicator, in milliseconds (M90b). Must be a positive finite number; anything else — zero, negative, NaN, Infinity — throws at plugin construction. The identical check runs in the barrel-exported HealthService constructor, so constructing the service directly cannot bypass it.

An indicator that has not settled within the deadline is recorded as { status: 'down', data: { reason: 'timeout' } }; one that rejects is recorded as { status: 'down', data: { reason: 'error' } }. Either way the report itself stays bounded, so a dead dependency can no longer leave the whole endpoint pending.