Multiplayer via git-based storage

[stphung]

Explore what multiplayer could look like using git as the shared storage backend.

Ideas to consider:

• Player save files stored in a shared git repo
• Async multiplayer (leaderboards, trading, shared world state) via commits/branches
• Conflict resolution for concurrent play sessions
• What interactions make sense (trading items, shared dungeons, PvP rankings, guild havens)
• How git merge semantics map to game state reconciliation
• Latency tolerance — what works with eventual consistency vs what needs real-time