graph TB
    subgraph Binary ["Server (Composition Root)"]
        server["server<br/><i>wires adapters, starts Axum</i>"]
    end

    subgraph Application ["Application Layer"]
        AppState["AppState"]
        PlacePixel["canvas::place_pixel"]
        GetState["canvas::get_state"]
        SaveSnapshot["canvas::save_snapshot"]
        RestoreSnapshot["canvas::restore_snapshot"]
        Connect["soldiers::connect"]
        Disconnect["soldiers::disconnect"]
        InMemoryCanvas["InMemoryCanvasStore"]
        InProcessBroadcast["InProcessBroadcaster"]
    end

    subgraph Domain ["Domain Layer (0 infra deps)"]
        Canvas["Canvas"]
        ValueObjects["Color | Position | PixelUpdate"]
        BroadcastEvent["BroadcastEvent"]
        DomainError["DomainError"]

        subgraph Ports ["Port Traits"]
            CanvasStore["CanvasStore"]
            CanvasPersistence["CanvasPersistence"]
            EventBroadcaster["EventBroadcaster"]
        end
    end

    subgraph Shared ["Shared Types"]
        Config["config<br/><i>AppConfig, ConfigSource trait</i>"]
        ApiTypes["api-types<br/><i>PixelUpdatePayload, event constants</i>"]
    end

    subgraph Adapters ["Adapters"]
        subgraph Transport ["Transport (driving)"]
            SocketIO["socketio<br/><i>Socket.IO protocol</i>"]
            WebSocket["websocket<br/><i>native WebSocket + JSON</i>"]
        end

        subgraph Infrastructure ["Infrastructure (driven)"]
            ConfigEnv["config-env<br/><i>env var loader</i>"]
            CanvasFile["canvas-file<br/><i>file snapshots</i>"]
            HttpAxum["http-axum<br/><i>HTTP routes, rate limit,<br/>embedded static files</i>"]
        end
    end

    server --> Application
    server --> Transport
    server --> Infrastructure
    server --> Config

    PlacePixel --> CanvasStore
    PlacePixel --> EventBroadcaster
    SaveSnapshot --> CanvasStore
    SaveSnapshot --> CanvasPersistence
    RestoreSnapshot --> CanvasStore
    RestoreSnapshot --> CanvasPersistence
    Connect --> EventBroadcaster
    Disconnect --> EventBroadcaster

    InMemoryCanvas -.->|implements| CanvasStore
    InProcessBroadcast -.->|implements| EventBroadcaster
    CanvasFile -.->|implements| CanvasPersistence
    ConfigEnv -.->|implements| Config

    SocketIO --> Application
    WebSocket --> Application
    SocketIO --> ApiTypes
    HttpAxum --> Config

    classDef domain fill:#e8f5e9,stroke:#2e7d32
    classDef app fill:#e3f2fd,stroke:#1565c0
    classDef adapter fill:#fff3e0,stroke:#e65100
    classDef shared fill:#f3e5f5,stroke:#6a1b9a
    classDef binary fill:#fce4ec,stroke:#c62828

    class Canvas,ValueObjects,BroadcastEvent,DomainError,CanvasStore,CanvasPersistence,EventBroadcaster domain
    class AppState,PlacePixel,GetState,SaveSnapshot,RestoreSnapshot,Connect,Disconnect,InMemoryCanvas,InProcessBroadcast app
    class SocketIO,WebSocket,ConfigEnv,CanvasFile,HttpAxum adapter
    class Config,ApiTypes shared
    class server binary