moq-lite-06: an oversize GOAWAY URI and a Message Length mismatch end only the stream; the session is never closed #5259

Problem

A decode error on a control stream (Announce, Subscribe, Goaway, ...) is logged and ends only that stream; the session is never closed. Two draft rules need a session close:

1. GOAWAY URI over 8,192 bytes (MUST). Draft section 7.18: "The URI MUST NOT exceed 8,192 bytes; a receiver MUST treat a longer URI as a protocol violation and MAY reject it based on the length prefix alone." The same section closes the session with PROTOCOL_VIOLATION for the other GOAWAY violations.
2. Message Length that disagrees with the content (SHOULD). Draft section 7.1: "An implementation SHOULD close the connection with a PROTOCOL_VIOLATION if it receives a message with an unexpected length."

Repro

Against moq as publisher over moq-lite-06, native QUIC or WebTransport:

1. Oversize GOAWAY: open a Goaway Stream (bidirectional, type 0x5) with a message claiming an 8193-byte URI: 05 60 03 60 01 61 61 ... (then 8193 bytes). The CLI resets the Goaway Stream with CANCELLED (0x1) about 2 ms later and sends STOP_SENDING 0. The session stays open for the whole 3 s I waited.
2. Length mismatch: open an Announce Stream with 01 04 00 6c 31 64 (stream type 0x1, Message Length 4, but the message is an empty Broadcast Path Prefix plus three trailing bytes). The CLI logs WARN moq_net::lite::message: decode failed err=long buffer and WARN moq_net::lite::publisher: control stream error err=long buffer, resets the stream with CANCELLED and sends STOP_SENDING 0. The session stays open.

Verified on moq 0.14.2 from main at 954505e (both cases reproduce) and on 0.14.1 at b8b0d23.

Where

• rs/moq-net/src/lite/goaway.rs decode_msg rejects a length above 8192 from the prefix alone (DecodeError::InvalidValue), as the draft allows.
• rs/moq-net/src/lite/message.rs reports trailing bytes as DecodeError::Long.
• rs/moq-net/src/lite/publisher.rs then treats both as a per-stream error: the comment "A decode error propagates to the caller, which logs and continues" explains that a malformed GOAWAY must not tear down the session it is trying to drain, and the control loop only logs per-stream errors.

Suggested fix

Map these two decode errors to a session close with PROTOCOL_VIOLATION on the control streams. A draining session can still be closed by a protocol violation; the draft does not exempt it. If the continue-on-error design is deliberate for other decode errors, the oversize GOAWAY URI (a MUST) still needs the close.

Found with an interop runner (mondain/moq-contribution-interop-runner, docs/moq-lite-punch-list.md items ML-05 and ML-03; rows L06-7-18-MUST-179 and L06-7-1-SHOULD-107). Drafted with AI assistance; the bytes and logs above are from real runs.