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/using-e2e/main.hako

@@ -0,0 +1,9 @@
+// using/nyash.link E2E sample (placeholder)
+static box Main {
+  init { }
+  main(args) {
+    // When using/nyash.link is active, modules can be resolved here.
+    // Placeholder just returns 0 for now.
+    return 0
+  }
+}