Fix duplicate diagnostics and integer expression error in 500 tracker

Issues fixed:
- Removed duplicate diagnostic messages (was showing same error 169+ times)
- Fixed bash integer expression error at line 552
- Deduplicate diagnostics by domain+url+issue combination using sort -u
- Only save diagnostics when we have an actual identified cause
- Skip displaying UNKNOWN causes (these are now categorized as NO_PHP_ERROR_LOGGED)
- Show "X unique issues" instead of raw count to reflect deduplication

Now shows each unique domain+issue combination once, with proper counts.

modules/website/500-error-tracker.sh

@@ -322,13 +322,17 @@ while IFS='|' read -r domain user status url timestamp ip; do
                 [ -n "$specific_file" ] && diagnosis="$diagnosis - from file: $specific_file"
             fi
 
-            # Save detailed diagnosis
+            # Save detailed diagnosis only if we identified a specific cause
+            if [ "$cause" != "UNKNOWN" ] && [ -n "$diagnosis" ]; then
                 echo "$cause|$diagnosis" >> "$DETAILED_DIAGNOSIS"
                 ((diagnosed_causes["$cause"]++))
                 [ -z "${cause_examples[$cause]}" ] && cause_examples["$cause"]="$diagnosis"
             else
                 ((diagnosed_causes["NO_PHP_ERROR_LOGGED"]++))
             fi
+        else
+            ((diagnosed_causes["NO_PHP_ERROR_LOGGED"]++))
+        fi
     else
         # No error log found - check .htaccess and permissions thoroughly
         if [ "$user" != "unknown" ]; then
@@ -510,6 +514,9 @@ done | sort -rn | while IFS='|' read count cause; do
             echo -e "${YELLOW}$clean_cause${NC} - $count occurrences"
             echo -e "   ${YELLOW}Note:${NC} 500 error but no PHP error in log - likely .htaccess or Apache config"
             ;;
+        UNKNOWN)
+            # Skip - these are errors we couldn't diagnose
+            ;;
         *)
             echo -e "${INFO_COLOR}$clean_cause${NC} - $count occurrences"
             ;;
@@ -544,17 +551,20 @@ echo " SPECIFIC DIAGNOSTICS (per URL/file)"
 echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
 echo ""
 
-# Show detailed diagnostics grouped by cause
+# Show detailed diagnostics grouped by cause - deduplicate by domain+url+issue
 if [ -f "$DETAILED_DIAGNOSIS" ] && [ -s "$DETAILED_DIAGNOSIS" ]; then
     for cause_type in PHP_MEMORY_EXHAUSTED PERMISSION_ERROR HTACCESS_ERROR PHP_FATAL_ERROR PHP_SYNTAX_ERROR MISSING_PHP_FUNCTION DATABASE_CONNECTION; do
-        cause_count=$(grep -c "^${cause_type}|" "$DETAILED_DIAGNOSIS" 2>/dev/null || echo "0")
+        # Get unique diagnostics (deduplicate identical domain+issue combinations)
+        unique_diags=$(grep "^${cause_type}|" "$DETAILED_DIAGNOSIS" 2>/dev/null | cut -d'|' -f2 | sort -u)
+        cause_count=$(echo "$unique_diags" | grep -c "^" 2>/dev/null || echo "0")
 
-        if [ "$cause_count" -gt 0 ]; then
+        if [ "$cause_count" -gt 0 ] && [ -n "$unique_diags" ]; then
             cause_display=$(echo "$cause_type" | tr '_' ' ')
-            echo -e "${RED}${BOLD}$cause_display ($cause_count)${NC}"
+            echo -e "${RED}${BOLD}$cause_display ($cause_count unique issues)${NC}"
             echo ""
 
-            grep "^${cause_type}|" "$DETAILED_DIAGNOSIS" | cut -d'|' -f2 | head -20 | while read -r diag_line; do
+            echo "$unique_diags" | head -20 | while read -r diag_line; do
+                [ -z "$diag_line" ] && continue
                 echo -e "  ${YELLOW}•${NC} $diag_line"
             done