fix: increase reconnection grace period from 5 to 15 minutes for better recovery

Author: nyxiereal

main.go

@@ -343,8 +343,8 @@ type Server struct {
 }
 
 const (
-	// Grace period for reconnection (5 minutes)
-	ReconnectGracePeriod = 5 * time.Minute
+	// Grace period for reconnection (increased from 5 to 15 minutes for better recovery)
+	ReconnectGracePeriod = 15 * time.Minute
 	// How often to clean up expired sessions
 	SessionCleanupInterval = 1 * time.Minute
 	// Security limits