WebSocket connection and subscription manager.

Manages multiple WebSocket connections, routes subscriptions to appropriate connections, and provides a registry of active subscriptions.

Connection Types

Subscriptions are categorized by their connection requirements:

• :shared - Can share a connection with other subscriptions (e.g., allMids, trades)
• :dedicated - Needs its own connection due to response format (e.g., l2Book with params)
• :user_grouped - Must share connection with other subs for same user (e.g., userFills)

Usage

# Subscribe to allMids (shared connection)
{:ok, sub_id} = Manager.subscribe(Hyperliquid.Api.Subscription.AllMids, %{})

# Subscribe to l2Book (dedicated connection per variant)
{:ok, sub_id} = Manager.subscribe(Hyperliquid.Api.Subscription.L2Book, %{
  coin: "BTC", nSigFigs: 5
})

# Subscribe to user fills (grouped by user)
{:ok, sub_id} = Manager.subscribe(Hyperliquid.Api.Subscription.UserFills, %{
  user: "0x1234..."
})

# Unsubscribe
:ok = Manager.unsubscribe(sub_id)

# List active subscriptions
Manager.list_subscriptions()

Architecture

The Manager uses a DynamicSupervisor to manage WebSocket connections. Each connection is a GenServer that handles the actual WebSocket communication. The Manager maintains:

1. A registry of active subscriptions (ETS table)
2. A mapping of subscription keys to connection PIDs
3. Connection metadata (shared vs dedicated, user grouping)