[ioredis] RESP3 attribute replies rejected as unknown type and kill the connection

## Observed symptom RESP3 attribute replies are rejected as an unknown type and kill the connection ioredis 6 defaults to `protocol: 3`, but the decoder has no case for the RESP3 attribute type (`|`, byte 124). When a server sends one, `lib/resp/decoder.ts` throws `Unknown RESP type 124 "|"`, and `DataHandler` turns that into a fatal protocol error: the pending command rejects, the socket is torn down, and every other command in flight on that connection is dropped. Needs a server that allows DEBUG: ## Literal error text ``` error event: Unknown RESP type 124 "|". Please report this. ``` ## Environment GitHub redis/ioredis #2212 ## Trigger / context Public GitHub report in redis/ioredis (FRESH_7D). ## Source evidence - https://github.com/redis/ioredis/issues/2212 (2026-10-02T02:01:21Z) — evidence_class: PRIMARY_ISSUE_REPORT — #2212 ## Freshness - classification: FRESH_7D - retrieved_at: 2026-10-02T09:49:02.645589Z - scout_id: C1218b5975e ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.