Make user history cleaning optional in trace eraser

User bash history cleaning is now optional with a prompt, since most users only work as root.

Changes:
• Added user count detection
• Prompts: "Clean user bash histories too? (y/n) [n]"
• Default is "no" (skip user histories)
• If no users exist, automatically skips
• Only cleans root history by default (faster, covers 99% of use cases)

This makes the script faster and more sensible for typical usage where only root is used to run the toolkit.

tools/erase-toolkit-traces.sh

@@ -73,9 +73,22 @@ if [ -f ~/.bash_history ]; then
     history -w
 fi
 
-# Clean bash history for all users
+# Clean bash history for all users (optional - skip if only root is used)
 echo "→ Checking user histories..."
+user_count=0
 for user_home in /home/*; do
+    [ -d "$user_home" ] && user_count=$((user_count + 1))
+done
+
+if [ "$user_count" -eq 0 ]; then
+    echo "  ✓ No user accounts found (skipped)"
+else
+    echo "  Found $user_count user account(s)"
+    echo ""
+    read -p "  Clean user bash histories too? (y/n) [n]: " clean_users
+
+    if [ "$clean_users" = "y" ] || [ "$clean_users" = "Y" ]; then
+        for user_home in /home/*; do
             if [ -f "$user_home/.bash_history" ]; then
                 username=$(basename "$user_home")
                 echo "  → Cleaning history for $username..."
@@ -94,7 +107,12 @@ for user_home in /home/*; do
                     echo "    ✓ Cleared (file had < 50 entries)"
                 fi
             fi
-done
+        done
+    else
+        echo "  ✓ Skipped user histories (only root cleaned)"
+    fi
+fi
+echo ""
 
 # Clean system logs (pattern-based for logs, not history)
 echo "→ Cleaning system logs..."