Fix: auto-updater download always failed with network error
Root cause: GitHub release asset URLs return HTTP 302 to a CDN (objects.githubusercontent.com) with a presigned URL. The downloader did not follow redirects, causing every update install attempt to fail with NUP_NET_FAIL.
Fixed in build 48 by following one redirect: on 3xx response the Location header is extracted, the output file is truncated, and a second HTTPS connection is made to the CDN. The update check (detecting that a new version exists) was always working correctly — only the actual download was broken.