Fix division by zero in progress indicator

- Add check for total=0 before calculating percentage
- Prevents crash when indexing empty user/database lists
- Displays 100% completion for empty lists

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/common-functions.sh

@@ -117,6 +117,13 @@ show_progress() {
     local current=$1
     local total=$2
     local message="$3"
+
+    # Avoid division by zero
+    if [ "$total" -eq 0 ]; then
+        printf "\r[INFO] Progress: [####################] 100%% - %s" "$message"
+        return
+    fi
+
     local percent=$((current * 100 / total))
     local bars=$((percent / 5))  # 20 chars wide