Bring main into release 57's branch, conflicts resolved

So the release branch carries what main gained, and the store-tests drop check passes again.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/link/queue.go

@@ -427,6 +427,9 @@ func ReadCheckBuilds(ctx context.Context, js *broker.JetStream, seat string, pul
 // safeKey is an id that can be a key, and a subject token, as it is: a build id, never a pattern.
 var safeKey = regexp.MustCompile(`^[A-Za-z0-9_-]+$`)
 
+// SafeBuildID says an id can be a subject token as it is: a build's id, never a pattern.
+func SafeBuildID(id string) bool { return safeKey.MatchString(id) }
+
 // Cancelled is what the controller writes for an ask it cancelled.
 type Cancelled struct {
 	At  string `json:"at"`