[TheMeinerLP]

Proposed changes

On the team proxy, following the leader into a game worked: the leader went from Lobby-2 to Bounce-1, and the member followed within a second. Coming back did not. After the leader's /lobby, the member stayed in the finished round, and after typing /lobby themselves landed on Lobby-1 while the leader was on Lobby-2. The party fell apart exactly when players expect it to stay together.

This proposes one rule for every move of the leader: a member follows if they were on the server the leader just left, or if they are idle in a lobby. A member in another game stays. That covers the round ending (game → lobby), today's case (lobby → game), and keeping the party in one lobby instance. To know where the leader came from, warps carry an optional origin (fromServer in the request, from in the event). Old plugins ignore it.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments

Ships as feat(party): bring the party back to the lobby with its leader. Rejected alternatives (tracking members' servers in the service, warping only on game → lobby) are recorded in the design. Party-aware lobby selection at login belongs to Titan and is out of scope.