test: run frontend verification natively under Bun

Make Bun the explicit Vitest runtime. Detect cyclic tool input before slow native pretty serialization, preserve shared references, and use native abort signals in the live jsdom probe. 2587 tests repeatedly green and2 real HTTP/UI tests pass; Bun-run typecheck, lint and production build pass without NODE_OPTIONS.

2 files changed, 22 insertions, 17 deletions

diff --git a/scripts/text-file-environment.ts b/scripts/text-file-environment.ts
new file mode 100644
index 0000000..6507be2
--- /dev/null
+++ b/scripts/text-file-environment.ts
@@ -0,0 +1,19 @@
+import type { Environment } from "vitest/environments";
+import { builtinEnvironments } from "vitest/environments";
+
+/** Real runtime fetch and AbortSignal must belong to the same implementation.
+ * jsdom supplies DOM APIs but replaces these globals with an incompatible realm.
+ * Keep the runtime's pair for this opt-in real-network component probe only.
+ */
+export default {
+  name: "text-file-jsdom",
+  transformMode: "web",
+  async setup(global, options) {
+    const controller = global.AbortController;
+    const signal = global.AbortSignal;
+    const environment = await builtinEnvironments.jsdom.setup(global, options);
+    global.AbortController = controller;
+    global.AbortSignal = signal;
+    return environment;
+  },
+} satisfies Environment;
diff --git a/scripts/text-file-live.test.ts b/scripts/text-file-live.test.ts
index 18d1cb6..3305616 100644
--- a/scripts/text-file-live.test.ts
+++ b/scripts/text-file-live.test.ts
@@ -2,24 +2,10 @@ import { type ChildProcess, spawn } from "node:child_process";
 import { rm, writeFile } from "node:fs/promises";
 import { resolve as resolvePath } from "node:path";
 import { createInterface } from "node:readline";
-import { transferableAbortController } from "node:util";
 import { fireEvent, render, screen } from "@testing-library/svelte";
 import { afterAll, beforeAll, describe, expect, it } from "vitest";
 import { createTextFileClient, Markdown } from "../src/features/markdown";
 
-// Bridge only the outer fetch edge's jsdom signal to Node's native signal.
-const networkFetch: typeof fetch = async (input, init) => {
-  const controller = transferableAbortController();
-  const abort = () => controller.abort();
-  init?.signal?.addEventListener("abort", abort, { once: true });
-  if (init?.signal?.aborted) controller.abort();
-  try {
-    return await fetch(input, { ...init, signal: controller.signal });
-  } finally {
-    init?.signal?.removeEventListener("abort", abort);
-  }
-};
-
 interface Fixture {
   url: string;
   path: string;
@@ -30,7 +16,7 @@ interface Fixture {
 
 // Opt-in real cross-repo UI/network probe. Owns an ephemeral loopback server and
 // temporary files only; never connects to or restarts the deployed application.
-// TEXT_FILE_LIVE_PROBE=1 bunx vitest run scripts/text-file-live.test.ts
+// bun run test:text-file-live
 // The backend must be installed and typechecked first (workspace public dists).
 describe.skipIf(process.env.TEXT_FILE_LIVE_PROBE !== "1")("live saved-file chat display", () => {
   let child: ChildProcess;
@@ -86,7 +72,7 @@ describe.skipIf(process.env.TEXT_FILE_LIVE_PROBE !== "1")("live saved-file chat
     const saved = Array.from({ length: 20 }, (_, i) => `## Saved step ${i + 1}`).join("\n");
     await writeFile(fixture.path, saved);
     const reply = "I saved the implementation plan.\n\n[Plan](text-file:plan%20100%25.md)";
-    const client = createTextFileClient(fixture.url, fixture.conversationId, networkFetch);
+    const client = createTextFileClient(fixture.url, fixture.conversationId, fetch);
     let view = render(Markdown, { text: reply, textFiles: client });
     try {
       await screen.findByRole("heading", { name: "Saved step 1" });
@@ -115,7 +101,7 @@ describe.skipIf(process.env.TEXT_FILE_LIVE_PROBE !== "1")("live saved-file chat
   });
 
   it("does not read the same local path for an authoritative remote conversation", async () => {
-    const client = createTextFileClient(fixture.url, fixture.remoteConversationId, networkFetch);
+    const client = createTextFileClient(fixture.url, fixture.remoteConversationId, fetch);
     const view = render(Markdown, {
       text: `[Remote](text-file:${encodeURI(fixture.path)})`,
       textFiles: client,