fix(sub): bound what a remote routing profile renders to

Remote routing sources are fetched documents the panel re-renders on
every subscription request. A Clash YAML document stays small through
aliases, which decode to one shared value but are written out in full,
so it now has to fit a 4 MiB written-size budget and 16 levels of
nesting when it is accepted (and when a persisted copy is loaded). A JSON
routing profile could repeat route groups, each copy repeating every
site list; a group now counts once, since a repeat can never match.

internal/sub/json_routing.go

@@ -210,7 +210,10 @@ func buildJsonRoutingSpec(object map[string]any) (jsonRoutingSpec, error) {
 	for _, segment := range strings.Split(order, "-") {
 		switch segment {
 		case "block", "proxy", "direct":
-			spec.RouteOrder = append(spec.RouteOrder, segment)
+			// A repeat can never match (the first rule wins) and would copy every list again.
+			if !slices.Contains(spec.RouteOrder, segment) {
+				spec.RouteOrder = append(spec.RouteOrder, segment)
+			}
 		}
 	}
 	return spec, nil