On some Windows PCs every app showed "Not available here" / "Offline" and
the tooltip said "invalid peer certificate: UnknownIssuer". We read the
Windows root store once with rustls-native-certs, but Windows only adds
many roots when something asks it to verify a chain. Chrome and Edge
verify on their own, so a PC that only uses them can lack the root
GitHub's certificate needs. Antivirus HTTPS scanning hits the same path.
Use ureq's platform-verifier feature (rustls-platform-verifier) so the OS
checks each chain itself and fetches missing roots. Linux still reads the
system store. No bundled root list comes in.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
