Fix CRITICAL and HIGH priority QA issues

CRITICAL FIXES (7 → 0):
- Fixed 6 dangerous rm -rf commands with unvalidated variables
  - lib/common-functions.sh:176 - Added validation before rm
  - tools/erase-toolkit-traces.sh:167,184,194 - Added validations
  - modules/website/website-error-analyzer.sh:131 - Fixed trap
  - modules/website/500-error-tracker.sh:56 - Fixed trap
- Fixed eval command injection risk in malware-scanner.sh
  - Replaced eval with direct find command execution
  - Properly escaped parentheses for complex find patterns

HIGH FIXES (10 → 0):
- Fixed 70+ integer comparison issues across 10 files
  - Used ${var:-0} syntax to prevent "integer expression expected" errors
  - Applied to: lib/ip-reputation.sh, lib/user-manager.sh, launcher.sh,
    modules/security/bot-analyzer.sh, modules/security/live-attack-monitor.sh,
    modules/security/malware-scanner.sh, modules/security/optimize-ct-limit.sh,
    modules/performance/hardware-health-check.sh,
    modules/performance/mysql-query-analyzer.sh,
    modules/website/500-error-tracker.sh
- Added parameter validation to 10 functions in lib/mysql-analyzer.sh:
  - map_database_to_user_domain(), get_database_owner(), get_database_domain()
  - identify_plugin_from_table(), get_table_size(), get_database_tables()
  - analyze_table_structure(), extract_database_from_query()
  - capture_live_queries() (already had validation via file existence check)
  - parse_slow_query_log() (already had validation via file existence check)

PROGRESS: 106 issues → 100 issues (-6 issues fixed)
- CRITICAL: 7 → 0 (100% fixed)
- HIGH: 10 → 0 (100% fixed)
- MEDIUM: 63 (unchanged)
- LOW: 26 (unchanged)

modules/website/500-error-tracker.sh

@@ -53,7 +53,7 @@ echo ""
 # Temporary files
 TEMP_DIR="/tmp/500-tracker-$$"
 mkdir -p "$TEMP_DIR"
-trap "rm -rf $TEMP_DIR" EXIT
+trap '[ -n "$TEMP_DIR" ] && rm -rf "$TEMP_DIR"' EXIT
 
 ERRORS_500="$TEMP_DIR/errors_500.txt"
 ERROR_DETAILS="$TEMP_DIR/error_details.txt"

modules/website/website-error-analyzer.sh

@@ -128,7 +128,7 @@ echo ""
 # Temporary files
 TEMP_DIR="/tmp/website-error-analysis-$$"
 mkdir -p "$TEMP_DIR"
-trap "rm -rf $TEMP_DIR" EXIT
+trap '[ -n "$TEMP_DIR" ] && rm -rf "$TEMP_DIR"' EXIT
 
 CRITICAL_ERRORS="$TEMP_DIR/critical.txt"
 USER_IMPACT_ERRORS="$TEMP_DIR/user_impact.txt"