**4 issues found** across 20 files

Prompt for AI agents (unresolved issues)

```text Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately. P1: `decode_consume_push` skips the documented leading `msg_count:u16`, which can misalign all subsequent field decoding for consume push frames. P3: The docs incorrectly say the API key is sent on every request; in this implementation it is sent once via an AUTH frame during connection setup. P1: `enqueue_single` raises `QueueNotFoundError` for every per-message failure, including non-queue-not-found errors. The old code had a `case` on the error code to distinguish queue-not-found from other failures. The per-message `err_code` is present in the FIBP response but is discarded in `Codec.decode_enqueue_response` (`_err_code`), so the client can't differentiate. The error code should be preserved in `EnqueueResult` and checked here. P0: **Deadlock**: `send_auth` is called before `start_reader`, but `send_auth` calls `request()` which blocks waiting for a response that only the reader thread can deliver. This deadlocks every connection that uses an API key. Swap the two lines so the reader thread is running before the AUTH request is sent. ```

_{Reply with feedback, questions, or to request a fix. Tag `@cubic-dev-ai` to re-run a review.}