feat: add multi-database support with generic environment variables

.env.example

@@ -30,6 +30,30 @@ PUBLIC_API_URL=http://localhost:3000/api
 # The public url used by clients to fetch assets
 PUBLIC_ASSETS_URL=http://localhost:3000/assets
 
+# ==============================================
+# DATABASE CONFIGURATION
+# ==============================================
+# Configure your database connection here.
+# 
+# Supported databases:
+# - PostgreSQL (DB_TYPE=pg)
+# - MySQL (DB_TYPE=mysql2) 
+# - SQLite (fallback - no configuration needed)
+#
+# If database environment variables are not provided,
+# the application will automatically fall back to SQLite.
+
+# Database type - specify the database engine to use
+# Options: 'pg' (PostgreSQL), 'mysql2' (MySQL)
+DB_TYPE=pg
+
+# Database connection details
+DB_HOST=localhost
+DB_PORT=5432
+DB_USER=your_username
+DB_PASSWORD=your_password
+DB_NAME=your_database_name
+
 # LiveKit (voice chat)
 LIVEKIT_WS_URL=
 LIVEKIT_API_KEY=

package.json

@@ -69,6 +69,10 @@
     "three-mesh-bvh": "^0.8.3",
     "yoga-layout": "^3.2.1"
   },
+  "optionalDependencies": {
+    "pg": "^8.16.0",
+    "mysql2": "^3.12.0"
+  },
   "devDependencies": {
     "@babel/eslint-parser": "^7.23.10",
     "@babel/preset-react": "^7.23.10",