### govern_backpressure

```{eval-rst}
.. plantuml::

   @startuml
   title Governance, Backpressure & Scaling
   top to bottom direction
   skinparam shadowing false
   rectangle "AlgoX2 Control Plane" as CP {
     [Namespaces/ACLs]
     [Policies (QoS, quotas)]
     [Admission Control]
   }
   rectangle "Data Plane" as DP {
     [Gateways]
     [Sequencers]
     [Storage]
   }
   
   rectangle "ClickHouse" as CH {
     [Consumers]
   }
   
   [Namespaces/ACLs] -down-> [Gateways]
   [Policies (QoS, quotas)] -down-> [Gateways]
   [Admission Control] -down-> [Gateways]
   
   [Consumers] -left-> [Gateways] : backpressure when lag↑
   [Gateways] -down-> [Sequencers] : scale independently
   [Sequencers] -down-> [Storage] : bounded journal files
   
   note right of CH
   - Multiple clusters can read same streams
   - No hot partitions, no rebal storms
   end note
   @enduml