fix(net): resolve subscription starts past skipped groups

quest/m1/README.md

@@ -102,7 +102,6 @@ lands before the cut.
 - [Resume reorder](/quest/m1/resume-reorder.md) - a group whose stream header arrives after its successor's still resumes on failover; only a dropped or long-gone group fails
 - [A widened max age re-offers cached groups](/quest/m1/resolved-demand.md) - a warm relay serves a reader with a wider max age the cached groups a cold relay would, with no wire change
 - [Drop set](/quest/m1/drop-set.md) - each cursor judges missing groups against its own budget, so a narrow reader drops promptly and a widening re-offers groups already reported dropped on lite-07
-- [SUBSCRIBE_OK names where delivery starts](/quest/m1/subscribe-ok-start.md) - a warm relay names the same start group as a cold one instead of groups it skipped as stale
 - [Resumed close](/quest/m1/resume-closed.md) - a resumed JS track keeps its declared end across copies, and its `closed` and `largest()` settle on a clean end
 - [Resumed in-flight groups](/quest/m1/resume-in-flight.md) - a replaced route copy stays while a group below its bound is in flight or it backs a handed-out group late, and no longer than the reader's budget
 - [Recovered group readiness](/quest/m1/resume-readable.md) - a recovered JS group's `readable()` ignores frames its replacement replays

quest/m1/archive/tracks.md

@@ -207,5 +207,4 @@ answer it. Wire: a new lite-07-wip stream.
 ## Related
 
 - [SUBSCRIBE_TRACKS](/quest/m1/archive/subscribe-tracks.md) - moq-transport answers and learns listings through this hook
-- [SUBSCRIBE_OK names where delivery starts](/quest/m1/subscribe-ok-start.md) - a warm relay answers like a cold one, found while building SUBSCRIBE_ALL
 - [Subscribe ranges](/quest/m1/subscribe-ranges/README.md) - the subscription shape each per-track SUBSCRIBE uses

rs/moq-net/benches/session.rs

@@ -107,6 +107,8 @@ struct Shape {
 	/// Whole groups each watched broadcast writes per round, so a serve loop finds a
 	/// backlog ready: the group rate a round stands in for.
 	burst: usize,
+	/// Cached groups per track before a join, whose older groups the live budget skips.
+	history: usize,
 	/// Bytes queued before a mock stream applies backpressure.
 	window: usize,
 	/// Read each group via a fresh FETCH rather than a live subscription.
@@ -126,6 +128,7 @@ impl Shape {
 		group_frames: FRAMES,
 		paced: false,
 		burst: 1,
+		history: 1,
 		window: 1024 * 1024,
 		fetch: false,
 	};
@@ -180,6 +183,11 @@ impl Shape {
 				String::new()
 			},
 			if self.fetch { "/fetch" } else { "" },
+			if self.history > 1 {
+				format!("/history={}", self.history)
+			} else {
+				String::new()
+			},
 		)
 	}
 }
@@ -753,7 +761,15 @@ fn join(c: &mut Criterion, name: &str, shapes: impl IntoIterator<Item = Shape>)
 						let cluster = Cluster::new(version, *shape).await;
 						let payload = Bytes::from(vec![0; shape.frame]);
 						for track in &cluster.tracks {
-							write_group(track, &payload, shape.group_frames);
+							for sequence in 0..shape.history {
+								let mut group = track.append_group().unwrap();
+								for _ in 0..shape.group_frames {
+									group
+										.write_frame(Timestamp::from_millis(sequence as u64).unwrap(), payload.clone())
+										.unwrap();
+								}
+								group.finish().unwrap();
+							}
 						}
 						cluster
 					})
@@ -1255,6 +1271,20 @@ fn session(c: &mut Criterion) {
 			})
 		}),
 	);
+	// A live join skips a cached prefix. Sweep publishers against that prefix so
+	// resolving one start cannot hide a scan of unrelated publishers or group IDs.
+	join(
+		c,
+		"stale",
+		[1, 8, 32].into_iter().flat_map(|publishers| {
+			[1, 64, 1024].map(move |history| Shape {
+				publishers,
+				history,
+				..base
+			})
+		}),
+	);
+
 	join(c, "relays", [1, 2, 8].map(|relays| Shape { relays, ..base }));
 
 	churn(c, "sessions", [1, 16, 128].map(|sessions| Churn { sessions, held: 16 }));