fix(cli): prefer real ffmpeg exe over cmd shim (#1958)

packages/cli/src/browser/ffmpeg.test.ts

@@ -1,5 +1,6 @@
 import { execSync } from "node:child_process";
 import { existsSync } from "node:fs";
+import { resolve } from "node:path";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
 vi.mock("node:child_process", () => ({ execSync: vi.fn() }));
@@ -23,6 +24,14 @@ afterEach(() => {
 });
 
 describe("findFFmpeg", () => {
+  it("prefers the real Windows exe when where lists a cmd shim first", async () => {
+    Object.defineProperty(process, "platform", { value: "win32", configurable: true });
+    mockExec.mockReturnValue("C:\\tools\\ffmpeg.cmd\r\nC:\\tools\\ffmpeg.exe\r\n");
+
+    const { findFFmpeg } = await import("./ffmpeg.js");
+    expect(findFFmpeg()).toBe(resolve("C:\\tools\\ffmpeg.exe"));
+  });
+
   it("falls back to a common install dir when `which` fails (GUI-launched PATH)", async () => {
     // Simulate a process whose PATH lacks /opt/homebrew/bin: `which ffmpeg` throws.
     mockExec.mockImplementation(() => {