test(js/net): quarantine the datagram session-close-after-end test and plan its fix

js/net/src/lite/datagram-tracks.test.ts

@@ -469,7 +469,9 @@ for (const alpn of [ALPN_05, ALPN_06, ALPN_07_WIP]) {
 // A track's end waits a host task for the datagrams received with it. A session close in
 // between finishes the track rather than cutting it off: the publisher already ended it.
 for (const alpn of [ALPN_05, ALPN_06, ALPN_07_WIP]) {
-	test(`${alpn}: a session close right after a datagram track's end keeps the end`, async () => {
+	// Quarantined: fails in the merge queue with "Session: remote error: 0" (lite-06 on #8280, lite-05 on
+	// #8276 after #8321 re-enabled it). /quest/m0/test-flakes-2/datagram-close-end.md
+	test.skip(`${alpn}: a session close right after a datagram track's end keeps the end`, async () => {
 		const source = new Origin();
 		const publication = source.route(path, { hidden: true });
 		const datagrams = publication.broadcast.createDatagrams("audio");

quest/m0/test-flakes-2/README.md

@@ -229,6 +229,12 @@ two random-mesh withdrawal tests, which hit nextest's 60 s kill in
 `just check` and are quarantined with `#[ignore]` by
 [moq-dev/moq#8336](https://github.com/moq-dev/moq/pull/8336).
 
+Added 2026-11-09 (maintainer's standing rule that flakes join this epic):
+`js/net`'s datagram session-close-after-end test again, whose lite-05 case
+failed the merge queue for [moq-dev/moq#8276](https://github.com/moq-dev/moq/pull/8276)
+after [moq-dev/moq#8321](https://github.com/moq-dev/moq/pull/8321) re-enabled it.
+It is quarantined with `test.skip` for every version until its child fixes it.
+
 Public API: none. Wire: none.
 
 ## Required
@@ -240,3 +246,4 @@ Public API: none. Wire: none.
 - [js/net's compressed-frame cap test holds up under load](/quest/m0/test-flakes-2/compressed-frame-cap.md) - the cap is proven without a 32 MiB payload, and its `test.skip` is removed
 - [js/net's lite-07 re-dropped re-offer test holds up under load](/quest/m0/test-flakes-2/redropped-reoffer.md) - update 3 is ordered before the re-offer opens by an event, not a yield count, and its `test.skip` is removed
 - [moq-net's random-mesh withdrawal tests fit the gate](/quest/m0/test-flakes-2/mesh-withdraw-runtime.md) - the 200-seed mesh tests cost seconds of CPU, and their `#[ignore]` is removed
+- [js/net's datagram session-close-after-end test holds up under load](/quest/m0/test-flakes-2/datagram-close-end.md) - the abort is ordered after the end by an event the client observes, and its `test.skip` is removed

quest/m0/test-flakes-2/datagram-close-end.md

@@ -0,0 +1,30 @@
+# [S] js/net's datagram session-close-after-end test holds up under load
+
+## Goal
+
+`js/net/src/lite/datagram-tracks.test.ts`'s "a session close right after a
+datagram track's end keeps the end" passes in the merge queue for every
+version it covers, and its `test.skip` is removed.
+
+## Plan
+
+Planned 2026-11-09 (maintainer's standing rule that flakes join this epic).
+The lite-06 case dropped
+[moq-dev/moq#8280](https://github.com/moq-dev/moq/pull/8280) from the merge
+queue and was quarantined; [moq-dev/moq#8321](https://github.com/moq-dev/moq/pull/8321)
+re-enabled it with no fix after finding no repro; its investigation, which rules
+out microtask reordering and names `Budget` before `connect` and `now()` in
+`group.ts`/`cache.ts` as the real-time suspects, stays in its PR body. The
+lite-05 case then failed the merge queue for
+[moq-dev/moq#8276](https://github.com/moq-dev/moq/pull/8276) with `Session:
+remote error: 0`: the reader saw the abort before the end. The land fixer's
+note on #8276 records 20 clean repeats of the file on a scratch merge, so it
+fails only under the queue's load.
+
+The test assumes 10000 microtask turns deliver the publisher's end before
+`client.abort()`. Find the step that still crosses a host task under load, and
+order the abort after the end by an event the client observes (such as the
+reader's track reaching its end state), never by more turns or a sleep. Then
+remove the `test.skip` and delete this quest.
+
+Public API: none. Wire: none.