fix(net): cancel abandoned IETF group fetches

doc/concept/standard.md

@@ -46,7 +46,10 @@ on moq-lite.
 On drafts 14–19, the Rust publisher answers a standalone `FETCH` within one
 group from the cache. A relay fetches a missing group upstream with a `FETCH`
 of that one whole group, and an upstream refusal is the refusal the fetcher
-sees. A range touching several groups is refused with `NOT_SUPPORTED`, as is
+sees. Once its last reader leaves, the relay cancels the upstream fetch, even
+before `FETCH_OK`, and aborts an incomplete group instead of caching it as whole.
+Drafts 14–16 use `FETCH_CANCEL`; drafts 17–19 stop and reset the request stream.
+A range touching several groups is refused with `NOT_SUPPORTED`, as is
 any `FETCH` on draft-20 and later, which moved the range into
 `LOCATION_FILTER`. A standalone `FETCH`
 carries no timestamps, since no `SUBSCRIBE_OK` declared a timescale for it.

quest/m1/README.md

@@ -54,7 +54,6 @@ QUIC studies there on that rule.
 - [Parked reads wake](/quest/m1/parked-read-wakes.md) - a read parked on an evicted or aborted group wakes and re-judges, for resume successors and plain tracks alike
 - [Reader end parity](/quest/m1/reader-end-parity.md) - JS readers see a track's end once the newest group reaches the declared end, as Rust readers do
 - [JS cache window](/quest/m1/js-prune-cache-window.md) - js/net ages idle groups on a cache window and keeps max_age as media-time staleness, as Rust does
-- [IETF FETCH abandonment](/quest/m1/ietf-fetch-abandonment.md) - the Rust moq-transport subscriber cancels a group FETCH once its last reader leaves
 - [A watch and publish release ships assets()](/quest/m1/assets-release.md) - the release that lets the sites host the worklets
 - [Dogfood hosted worklets](/quest/m1/dogfood-assets.md) - moq.dev and the moq.pro dashboard host the worklets and call `assets()` after the release
 - [More tests under load](/quest/m1/test-flakes-2/README.md) - the second round of load-only failures, one quest per flake, fixed at the cause

quest/m1/demand-everywhere.md

@@ -41,6 +41,5 @@ its race still needs an owner.
 
 Public API: breaking in moq-net and `@moq/net`. Wire: none.
 
-## Related
-
-- [IETF FETCH abandonment](/quest/m1/ietf-fetch-abandonment.md) - first new consumer of group request demand; can ship on `poll_unused` without waiting for this
+Migrate the IETF FETCH cancellation's request watch from `poll_unused` to
+`demand().poll_unused` along with the other handlers.