Using scopes in Effect to manage resources like temporary directories is a good approach. Your cu...

export const DownloadHandler = Effect.gen(function*() {
  const params = yield* HttpServerRequest.schemaSearchParams(UrlParams);
  const scope = yield* Scope.make();

  yield* Effect.addFinalizer(() => Scope.close(scope, Exit.succeed(void 0)));

  const { id, outputPath } = yield* hlsToMp4(params.link).pipe(
    Scope.extend(scope),
  );
  yield* Effect.logInfo("Sending file", { outputPath });

  return yield* HttpServerResponse.file(outputPath, {
    headers: {
      "Content-Disposition": `attachment; filename="${id}.mp4"`,
    },
  });
})