Jellify (and other @jellyfin/sdk clients) that connect by raw address fall
back to HTTP when TLS isn't available, then adopt the handshake's
LocalAddress as their server base URL. We never populated it, so Jellify's
SDK `api` object was undefined and sign-in crashed with "Cannot read
property 'configuration' of undefined" (getUserApi(api!) with an undefined
api). Over an HTTPS connection Jellify uses connectionType=hostname and
never reads LocalAddress, which is why it worked while an HTTPS proxy was
in front.
Populate LocalAddress from the request — scheme + host (honoring
X-Forwarded-*), plus the /jellyfin mount path — matching real Jellyfin,
which always sends it. Export server.ServerAddress for the resolution.