Fix security vulnerabilities. Add logging

.env.example

@@ -8,5 +8,15 @@ SECRET_KEY=replace-with-a-random-64-char-hex-string
 # Port configuration
 APP_PORT=8000
 
+# CORS allowed origins (comma-separated)
+CORS_ORIGINS=http://localhost:8000
+
+# Trusted proxy IPs for correct client IP extraction (comma-separated)
+TRUSTED_PROXY_IPS=127.0.0.1
+
 # Database path (default: ./data/gates.db relative to project root)
 # DATABASE_URL=sqlite:///./data/gates.db
+
+# Logging configuration
+LOG_LEVEL=INFO
+#LOG_FILE=logs/app.log