Function event_exceeds_max_nesting_cost 

pub fn event_exceeds_max_nesting_cost(event: &Event) -> Option<(usize, usize)>

Checks whether an event’s nesting frame cost exceeds the safe limits for protobuf encoding.

Returns Some((cost, budget)) identifying the path that violated its budget, or None if the event is within bounds.

Every arbitrary value is checked against MAX_VALUE_NESTING_FRAMES.

For metrics, only metadata is checked since metric values have a fixed structure.