Fix: Replace remaining C-style increment operators

ISSUE: Found 8 additional instances of C-style ((var++)) syntax that
weren't caught in previous comprehensive checks.

FIXES:
- Line 2053: SCANNERS_COMPLETED++ → var=$((var + 1))
- Line 2777: running_count++ → var=$((var + 1))
- Line 2788: completed_count++ → var=$((var + 1))
- Line 2797: error_count++ → var=$((var + 1))
- Line 2854: i++ → var=$((var + 1))
- Line 2876: deleted++ → var=$((var + 1))
- Line 3207: i++ → var=$((var + 1))
- Line 3275: i++ → var=$((var + 1))

All instances replaced using replace_all to ensure consistency.
These were missed in earlier comprehensive scans.

VERIFIED: bash -n syntax check passes

modules/security/malware-scanner.sh

@@ -2050,7 +2050,7 @@ for scanner in "${available_scanners[@]}"; do
     esac
 
     echo "" | tee -a "$SUMMARY_FILE"
-    ((SCANNERS_COMPLETED++))
+    SCANNERS_COMPLETED=$((SCANNERS_COMPLETED + 1))
 
     # Wait between scanners
     if [ "${SCANNERS_COMPLETED:-0}" -lt "$TOTAL_SCANNERS" ]; then
@@ -2774,7 +2774,7 @@ check_standalone_status() {
         # Use pgrep with exact match to avoid false positives from viewers/editors
         if pgrep -f "bash $dir/scan.sh" > /dev/null 2>&1 || [ -f "$dir/.scan_running" ]; then
             echo -e "  ${GREEN}●${NC} $session_name [RUNNING]"
-            ((running_count++))
+            running_count=$((running_count + 1))
 
             # Show progress if available
             if [ -f "$dir/logs/session.log" ]; then
@@ -2785,7 +2785,7 @@ check_standalone_status() {
             # Check if completed successfully
             if grep -q "Multi-Scanner Session Complete\|Scan session ended" "$dir/results/summary.txt" 2>/dev/null; then
                 echo -e "  ${CYAN}✓${NC} $session_name [COMPLETED]"
-                ((completed_count++))
+                completed_count=$((completed_count + 1))
 
                 # Show infected count if available
                 if [ -f "$dir/results/infected_files.txt" ] && [ -s "$dir/results/infected_files.txt" ]; then
@@ -2794,7 +2794,7 @@ check_standalone_status() {
                 fi
             else
                 echo -e "  ${RED}✗${NC} $session_name [ERROR/INCOMPLETE]"
-                ((error_count++))
+                error_count=$((error_count + 1))
             fi
         else
             echo -e "  ${YELLOW}?${NC} $session_name [UNKNOWN - no results yet]"
@@ -2851,7 +2851,7 @@ delete_standalone_sessions() {
         fi
 
         echo -e "  $i. $session_name [$status]"
-        ((i++))
+        i=$((i + 1))
     done
 
     echo ""
@@ -2873,7 +2873,7 @@ delete_standalone_sessions() {
                 if ! pgrep -f "$dir/scan.sh" > /dev/null 2>&1; then
                     echo "Deleting: $(basename "$dir")"
                     rm -rf "$dir"
-                    ((deleted++))
+                    deleted=$((deleted + 1))
                 fi
             done
             echo ""
@@ -3204,7 +3204,7 @@ view_scan_results() {
             local i=1
             for scanner in "${available_scanners[@]}"; do
                 echo "  $i. ${scanner^}"
-                ((i++))
+                i=$((i + 1))
             done
             echo ""
 
@@ -3272,7 +3272,7 @@ view_scan_results() {
                 fi
 
                 echo "  $i. $session_name [$status]"
-                ((i++))
+                i=$((i + 1))
             done
             echo ""