phase: 20.49 COMPLETE; 20.50 Flow+String minimal reps; 20.51 selfhost v0/v1 minimal (Option A/B); hv1-inline binop/unop/copy; docs + run_all + CURRENT_TASK -> 21.0

apps/tmp_new_array_plugin.hako

@@ -0,0 +1,7 @@
+static box Main {
+  main() {
+    local a
+    a = new ArrayBox()
+    return a.length()
+  }
+}