shovel: change logging fields order

I like it when the left side of a log line doesn't change as much as the
right.

shovel/task.go

@@ -431,13 +431,13 @@ func (task *Task) Converge() error {
 				return fmt.Errorf("committing tx: %w", err)
 			}
 			slog.InfoContext(ctx, "converge",
-				"src", task.srcName,
-				"dst", task.destConfig.Name,
 				"n", last.num,
 				"h", fmt.Sprintf("%.4x", last.hash),
 				"nrows", last.nrows,
 				"nrpc", wctx.Counter(ctx),
 				"nblocks", delta,
+				"src", task.srcName,
+				"dst", task.destConfig.Name,
 				"elapsed", time.Since(t0),
 			)
 			return nil

wslog/slog.go

@@ -106,6 +106,11 @@ func (h *Handler) Handle(ctx context.Context, r slog.Record) error {
 		*bufp = buf
 		freebuf(bufp)
 	}()
+	if len(r.Message) > 0 {
+		buf = append(buf, 'm', 's', 'g', '=')
+		buf = append(buf, []byte(r.Message)...)
+		buf = append(buf, ' ')
+	}
 	buf = append(buf, h.preformat...)
 	for _, f := range h.ctxs {
 		k, v := f(ctx)
@@ -126,12 +131,6 @@ func (h *Handler) Handle(ctx context.Context, r slog.Record) error {
 		buf = h.appendAttr(buf, h.prefix, a)
 		return true
 	})
-
-	if len(r.Message) > 0 {
-		buf = append(buf, 'm', 's', 'g', '=')
-		buf = append(buf, []byte(r.Message)...)
-	}
-
 	buf = bytes.TrimSuffix(buf, []byte(" "))
 	buf = append(buf, '\n')
 	h.mu.Lock()