Add tokio on server

Cargo.toml

@@ -26,6 +26,7 @@ rand = "0.10.1"
 serde = { version = "1.0.228", features = ["derive"] }
 thiserror = "2.0.18"
 tower-http = { version = "0.7.0", optional = true, features = ["fs"] }
+tokio = { version = "1.52.3", optional = true }
 tower-sessions-redis-store = { version = "0.16.0", optional = true }
 tracing = "0.1.44"
 
@@ -42,6 +43,7 @@ server = [
   "dep:dotenvy",
   "dep:fred",
   "dep:pbkdf2",
+  "dep:tokio",
   "dep:tower-http",
   "dep:tower-sessions-redis-store",
 ]