flowchart TB
    subgraph clients["Clients"]
        app["Web app (PWA)"]
        hacs["HACS integration"]
        bridge["ESP32 bridge"]
    end

    gw["Gateway (Traefik)"]

    subgraph services["Services"]
        identity["Identity"]
        fleet["Fleet"]
        dgw["Device-Gateway"]
        telemetry["Telemetry"]
        realtime["Realtime"]
        scheduler["Scheduler"]
        planner["Planner"]
        notif["Notifications"]
        entitle["Entitlements"]
        billing["Billing (optional)"]
        vision["Vision (AI assist)"]
    end

    nats[("NATS JetStream")]
    fga["OpenFGA"]
    pg[("PostgreSQL: one database per service")]

    app --> gw
    hacs --> gw
    bridge --> gw
    gw --> identity
    gw --> fleet
    gw --> realtime
    gw --> dgw
    gw --> telemetry
    gw --> notif
    gw --> entitle
    gw --> planner
    identity --> fga
    entitle --> fga
    planner --> fga
    fleet --> fga
    notif --> fga
    fga --> pg
    identity --> pg
    fleet --> pg
    telemetry --> pg
    scheduler --> pg
    notif --> pg
    entitle --> pg
    planner --> pg
    billing --> pg
    vision --> pg
    fleet <--> nats
    dgw <--> nats
    telemetry <--> nats
    realtime <--> nats
    scheduler <--> nats
    notif <--> nats
    billing <--> nats
    planner <--> nats
    vision <--> nats
    entitle <--> nats
    planner <--> nats