fix(quic): keep completion out of probe reset history

quest/m0/nightly/README.md

@@ -38,4 +38,4 @@ Public API: none. Wire: none.
 - [Feature shapes per crate](/quest/m0/nightly/hls-poll-closed-gate.md) - moq-hls `Broadcaster::poll_closed` is gated on `server`, and the gate checks each crate's feature shapes in isolation
 - [moq-relay tests build without default features](/quest/m0/nightly/relay-tests-features.md) - the integration tests gate their websocket and unix-socket fields on the features that define them
 - [qmux builds clean for iOS](/quest/m0/nightly/qmux-ios-dead-code.md) - `TcpStats` is gated to the platforms that implement it, so the iOS simulator build has no dead code
-- [Probe against Cubic](/quest/m0/nightly/competing-cubic.md) - the `competing_cubic` probe test stops resending a stream after its reset
+- [Probing beside Cubic](/quest/m0/nightly/competing-cubic.md) - the `competing_cubic` probe test stays within its deadline budget

quest/m0/nightly/competing-cubic.md

@@ -1,17 +1,21 @@
-# [S] Probe against Cubic passes
+# [S] Probing beside Cubic meets the deadline budget
 
 ## Goal
 
 `tests::probe::competing_cubic` in `rs/moq-quic/src/tests/probe.rs`, run by
-Nightly through `just rs quic-sim`, passes on `main`, fixed at its cause.
+Nightly through `just rs quic-sim`, passes its deadline budget on `main`,
+fixed at its cause.
 
 ## Plan
 
-[moq-dev/moq#6719](https://github.com/moq-dev/moq/pull/6719) found it failing
-the same way on `main` and on its branch: a probe resends a stream after that
-stream was reset. A reset stream's data is never retransmitted, so find which
-path still queues it (probe padding, a loss-recovery retransmit, or a stale
-send queue entry) and stop it there. The other probe tests in the release
-suite pass, so the fix must keep them passing.
+Over seeds 1 through 8, probing beside a Cubic upload averages 413.6 late
+frames versus 385.1 for the baseline, beyond the `LATE` budget. Find why
+probing adds delay beside Cubic and fix it in the transport. Keep the
+overhead, fairness, and rise budgets and the other probe scenarios passing.
+Do not relax the assertions or disable probing to make the scenario pass.
+
+Run the probe suite with release debug assertions and overflow checks, as
+`just rs quic-sim` does. `just rs test --release -p moq-quic --run-ignored all
+--no-fail-fast -E 'test(/^tests::probe::/)'` also includes the short gate cases.
 
 Public API: none. Wire: none.

rs/moq-quic/src/tests/probe.rs

@@ -472,7 +472,7 @@ fn expire(pair: &mut Pair, ch: ConnectionHandle, groups: &mut [Group], now: Inst
 		let mut stream = pair.client_send(ch, group.id);
 		let offset = stream.offset();
 		let Ok(false) = stream.acked(offset) else {
-			group.reset = Some(ended);
+			// Completion is not a reset: older probe packets may still be in flight.
 			continue;
 		};
 		stream.reset(VarInt(0)).unwrap();