Federated users (e.g. youruser@nova browsing orbit) could not add
instances via Settings → Connections because connectToRemote assumed
window.location.host was the home instance, producing a double-@ username
like youruser@nova.ddns.net@orbit.ddns.net that failed server
validation. Now derives trueHomeHost/bareUsername/trueHomeUserId from the
user's actual homeInstance fields and branches the auth flow: login-only
with bare username when targeting home, register with correct namespacing
for third-party remotes. Also skips profile sync to home instance since
it's the source of truth.
Jannis Braun
10be7a44f8