Function select_semantic_connection_capacity 

pub const fn select_semantic_connection_capacity(
    tracking: ConnectionConversationTracking,
    current: CapacityCounter,
) -> SemanticConnectionCapacityDecision

Applies semantic connection-conversation capacity before participant mutation.

An already tracked conversation succeeds without incrementing the counter, even when capacity is full. An untracked conversation either returns the complete incremented counter or the signed limit for the caller’s exact request-bound 0x0102 wire outcome.