Binance retired its legacy futures websocket and split quote
traffic across `/public` and `/market`. Route `bookTicker` and
`aggTrade` through dedicated URLs, merge both sockets, and accept
the new `st` stream-type field.
Bound connection and first-quote startup so failed or silent
streams raise `DataUnavailable` instead of hanging `datad` and
chart consumers.
Also,
- derive feed mode from resolved `FutesPair` metadata
- keep direct URL subscriptions stable across reconnects
- cover USD-M routes, payloads, and startup timeouts
Prompt-IO: ai/prompt-io/opencode/20260826T222600Z_5f631e19_prompt_io.md
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))
Gud Boi