Match relay in the save/login service: WebSocket rooms, seats, ready, 100 ms turn confirmation and checksum relay

server/Cargo.toml

@@ -6,12 +6,13 @@ license = "MIT"
 description = "Savegame storage service for DungeonCraft"
 
 [dependencies]
-axum = "0.8"
+axum = { version = "0.8", features = ["ws"] }
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "fs", "sync", "time"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 argon2 = "0.5"
 getrandom = "0.2"
+futures-util = "0.3.34"
 
 [profile.release]
 opt-level = 3