Animal breeding, taming and AI goals

[xRookieFight]

Problem

PassiveBehaviour covers idle wandering and death. There is no breeding (no love mode, no baby entities, no growth), no taming (wolves, cats, horses, parrots), no following a held item, no leashing, no panic, and no mob specific goals. Animal husbandry as a game loop does not exist.

Proposed solution

• A composable goal/behaviour system so mobs can be described as a prioritised goal list instead of one monolithic tick.
• Breeding: breeding items, love mode, cooldown, baby entities with a growth timer and growth acceleration.
• Taming for the tameable mobs, with owner persistence and sit/follow states.
• Follow-held-item, panic, avoid-entity, and mate goals.

Scope

entity/behaviour.v, entity/persistence.v, entity/registry.v. Depends on wider entity coverage.