Let the watchman read and delete a given-up message only on the streams dead letters come from, each by name and never a bucket's, so keeping dead letters cannot read every bucket (issue 1952 S5)

go/buscompose/users.go

@@ -229,6 +229,9 @@ func Users(r Records) ([]Principal, error) {
 			})
 			// **The grants part creates what a manifest declares** (novox/hq ADR 0547 §5; the operator, 2026-10-26
 			// 08:54): every placed module's buckets, logs and streams, each by its stream's name.
+			if d.Module == WatchmanModule {
+				out[len(out)-1].DeadLetterSources = deadLetterSourcesOf(r)
+			}
 			if d.Module == GrantsModule {
 				out[len(out)-1].CreatesStreams = declaredStreamsOf(r)
 				grants = len(out) - 1