fix(release): 收紧分发热路径与事务边界

internal/api/release_http.go

@@ -194,9 +194,18 @@ func (s *Server) loadReleaseDistributionFrom(r *http.Request, params backendrpc.
 	}
 	pageSize := 1000
 	result, err := backend.ReleaseDistribution(r.Context(), params)
-	if err != nil || result == nil || !result.Available || result.Total <= len(result.Entries) {
+	if err != nil || result == nil || !result.Available {
 		return result, err
 	}
+	if params.Destination != "" {
+		if result.Total != 1 || result.Offset != 0 || result.Limit != 1 || len(result.Entries) != 1 {
+			return nil, &releaseSelectorError{message: "Rust single-entry release distribution response is invalid"}
+		}
+		return result, nil
+	}
+	if result.Total <= len(result.Entries) {
+		return result, nil
+	}
 	all := append([]backendrpc.ReleaseDistributionEntry(nil), result.Entries...)
 	for offset := len(all); offset < result.Total; {
 		next, nextErr := backend.ReleaseDistribution(r.Context(), backendrpc.ReleaseDistributionParams{