WebSocket: live candles, trades and board feeds

Upgrade to a WebSocket. No key needed, rate-limit exempt, up to 8 channels per connection. With an API key (X-API-Key, or ?apiKey= from a browser) the connection joins a separate pool: up to 64 channels per connection and 20 connections per key (429 beyond). Subscribe with {op:"sub", channel:"candles", token, tf}, {op:"sub", channel:"trades", token} or {op:"sub", channel:"prices", chain} (chain 5042, 4663 or 143); the server pushes candle, trades and prices frames (every print within ~400 ms; on 5042 / 4663 each item also carries the token's live 24h volume and trade counts), new frames for tokens trading for the first time (5042 / 4663), ping every 25 s, and error with a code (bad_op · bad_token · bad_tf · bad_chain · channel_cap). Full protocol under Concepts → Streaming.