fix: reject control characters in manifest URLs

packages/contract/test/contract.test.ts

@@ -5,6 +5,7 @@ import {
   loadToolboxContext,
   parseToolboxApp,
   parseToolboxCatalog,
+  resolveWebUrl,
   type ToolboxAppManifest,
 } from "../src/index.js";
 import { describe, expect, it, vi } from "vitest";
@@ -179,6 +180,21 @@ describe("same-origin discovery", () => {
 });
 
 describe("loading and links", () => {
+  it.each([
+    ["TAB", "\t"],
+    ["LF", "\n"],
+    ["CR", "\r"],
+    ["C0", "\u0001"],
+    ["DEL", "\u007f"],
+  ])("rejects %s in URL helper string inputs", (_name, control) => {
+    expect(() =>
+      resolveWebUrl(`./before${control}after`, "https://tools.example.test/"),
+    ).toThrow(/control characters/u);
+    expect(() =>
+      resolveWebUrl("./tool", `https://tools.example.test/${control}`),
+    ).toThrow(/control characters/u);
+  });
+
   it("loads a catalog, resolves manifests and URLs, and supports external apps", async () => {
     const fetch = vi.fn(
       async (input: string | URL | Request, init?: RequestInit) => {