WS dispatch: error envelope on unrecognized sid is dropped silently

[TexasCoding]

From Wave 5 WebSocket audit, finding F-P-13. Severity: medium.

Code

kalshi/ws/dispatch.py:79-83 routes to on_error only when msg_type == "error". Top-level error envelopes are handled correctly.

The gap

The AsyncAPI spec also allows server-side errors tied to a specific subscription's sid (e.g., an error mid-stream for a sub that's still active). If the server sends a message with type other than "error" but carries error semantics (e.g., schema-violating payload, malformed message), it falls through to the unknown-type log path at dispatch.py:86-95 and is silently dropped.

Suggested fix

Either:

• Document that only top-level type="error" envelopes are routed to on_error; channel-level errors must be inspected by the consumer.
• Or extend the dispatcher to also check for an error payload field on otherwise-typed messages and route those to on_error.

Pin whichever behavior is intentional with a regression test.