refact: migrate sqlx + sqlite to tokio-postgresql

server/relay-server/src/lobby.rs

@@ -6,7 +6,7 @@
 
 use bytes::Bytes;
 use serde::{Deserialize, Serialize};
-use sqlx::SqlitePool;
+use deadpool_postgres::Pool;
 use std::collections::HashMap;
 use std::sync::Arc;
 use tokio::fs;
@@ -57,12 +57,12 @@ pub struct AppState {
     pub rooms: Mutex<HashMap<String, Room>>,
     /// Contains a mapping from game name to the maximum amount of players allowed.
     pub configs: RwLock<HashMap<String, u16>>,
-    /// SQLite connection pool — shared across all request handlers.
-    pub db: SqlitePool,
+    /// PostgreSQL connection pool — shared across all request handlers.
+    pub db: Pool,
 }
 
 impl AppState {
-    pub fn new(db: SqlitePool) -> Self {
+    pub fn new(db: Pool) -> Self {
         Self {
             rooms: Mutex::new(HashMap::new()),
             configs: RwLock::new(HashMap::new()),