Fix: Add guard to prevent division by zero at line 2359

The max_bot_traffic variable is extracted from a file which could
theoretically contain all zeros, causing division by zero. Added:
  max_bot_traffic=${max_bot_traffic:-1}

This ensures the denominator is never zero while preserving the
intended logic when valid data exists.

modules/security/bot-analyzer.sh

@@ -2352,6 +2352,7 @@ generate_report() {
         echo ""
         echo "Bot Traffic Timeline (hourly):"
         max_bot_traffic=$(awk '{print $1}' "$TEMP_DIR/hourly_bot_traffic.txt" | sort -rn | head -1)
+        max_bot_traffic=${max_bot_traffic:-1}  # Prevent division by zero
         while read -r line; do
             count=$(echo "$line" | awk '{print $1}')
             hour=$(echo "$line" | awk '{print $2}')