Module limits 

Tree-wide host admission. One lock checks and reserves every limit together; a reservation that never reaches persistence is rolled back on drop. Once persistence starts, an unknown write outcome retains lifetime capacity.

Structs

ActiveChildPermit

Retained by the host for the entire child turn, including waits on descendants. Releasing it frees concurrency but cannot erase a committed child from the tree.

AgentTreeAdmission

Cloneable host-side admission gate shared by all adapters in a root run.

AgentTreeCounts

Inspectable counters include in-flight reservations to prevent oversubscription.

AgentTreeLimits

Root-run ceilings. Child requests may only reduce them; zero disables admission.

ChildReservation

Admission guard. Drop before persistence rolls back both counters. Drop during persistence retains the unknown child’s lifetime count but releases concurrency; confirmed commit transfers concurrency to a live-turn permit.

Enums

AgentLimitError

Typed admission refusals; none silently queue or widen a limit.