Automatic manager state machine

Both LiquidManager and VegetationManager follow the same pattern: an in-memory set of active positions is mutated by world events, consumed by the tick, and produces WorldUpdate broadcasts to all clients.

stateDiagram-v2
    direction LR

    state "LiquidManager" as LIQ {
        [*] --> active : WATER placed / adjacent block removed
        active --> flowing : tick — can flow
        flowing --> active : spread continues
        flowing --> settled : no AIR neighbor (remove from set)
        settled --> [*]
    }

    state "VegetationManager" as VEG {
        [*] --> tracking : SEED placed on vegetationHost (tryActivate)
        tracking --> tracking : ticks < ticksRequired (accumulate every 40 ticks)
        tracking --> next_stage : ticks >= ticksRequired (SEED->SPROUT->SAPLING)
        next_stage --> tracking : stageIndex++ / new random ticksRequired
        next_stage --> spawning : last stage reached
        spawning --> [*] : oakTreeBlocks / pineTreeBlocks -> WorldUpdate batch
        tracking --> [*] : block missing (player broke it)
    }

See Liquids and Vegetation for the player-facing behaviour and the YAML that tunes each chain.