### arch_live_hist

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

   @startuml
   title Architecture (Dual-Path: Live + History)
   top to bottom direction
   skinparam shadowing false
   skinparam componentStyle rectangle
   
   package "Producers" as P {
     [Apps/Services]
   }
   
   package "AlgoX2 Data Plane" as X2 {
     [Kafka-compatible Gateway] as GW
     [Sequencer] as SQ
     [Storage (NVMe/Object)] as ST
     [Materializer\n(Iceberg Writer)] as MAT
   }
   
   cloud "S3 / MinIO" as S3
   database "Iceberg Tables" as ICE
   
   package "ClickHouse Cluster(s)" as CH {
     [Kafka Engine Tables] as CHK
     [MergeTree / ReplacingMergeTree] as CHMT
     [External Iceberg Reader] as CHI
   }
   
   ' Live path
   P --> GW : events (Kafka API)
   GW --> SQ : append
   SQ --> ST : commit
   ST --> CHK : consume (Kafka engine)
   
   ' History path
   ST --> MAT : window/notify
   MAT --> ICE : write snapshots
   ICE ..> S3
   
   ' Query paths
   CHK --> CHMT : MV ingest → dedupe via x2_seq
   CHI --> ICE : historical scans
   
   ' Fan-out (multicast)
   GW -down-> [CH Cluster #2]
   GW -down-> [CH Cluster #3]
   
   note right of CHMT
   - Use ReplacingMergeTree(x2_seq)
   - idempotent producers
   - at-least-once → duplicate-safe
   end note
   
   note bottom of GW
   QoS, quotas, namespaces, ACLs, TLS
   Multicast → no per-consumer duplication
   end note
   @enduml