fix(uninstall): enhance receipt file processing safety and prevent system file deletion

CRITICAL SECURITY FIX

Enhanced the receipt file parsing in uninstall operations to prevent
accidental deletion of critical system files while maintaining deep
cleanup capabilities.

Changes:
- Tightened whitelist in find_app_receipt_files() to exclude /Users/*,
  /usr/*, and /opt/* broad patterns
- Added explicit blacklist for /private/* with safe exceptions for
  logs, temp files, and diagnostic data
- Integrated should_protect_path() check for additional protection
- Added file deduplication with sort -u to prevent duplicate deletions
- Removed dry-run feature from batch uninstall (unused entry point)

Path Protection:
✅ Blocked: /etc/passwd, /var/db/*, /private/etc/*, all system binaries
✅ Allowed: /Applications/*, specific /Library/* subdirs, safe /private/* paths
✅ Additional: Keychain files, system preferences via should_protect_path()

This fixes a critical security issue where parsing .bom receipt files
could result in deletion of system files like /etc/passwd and /var/db/*,
leading to system corruption and data loss.

Affects: V1.12.14 and later versions
Testing: Validated against critical system paths, all blocked correctly

lib/core/file_ops.sh

@@ -66,14 +66,50 @@ validate_path_for_deletion() {
             ;;
     esac
 
+    # Allow known safe paths under /private
+    case "$path" in
+        /private/tmp | /private/tmp/* | \
+            /private/var/tmp | /private/var/tmp/* | \
+            /private/var/log | /private/var/log/* | \
+            /private/var/folders | /private/var/folders/* | \
+            /private/var/db/diagnostics | /private/var/db/diagnostics/* | \
+            /private/var/db/DiagnosticPipeline | /private/var/db/DiagnosticPipeline/* | \
+            /private/var/db/powerlog | /private/var/db/powerlog/* | \
+            /private/var/db/reportmemoryexception | /private/var/db/reportmemoryexception/*)
+            return 0
+            ;;
+    esac
+
     # Check path isn't critical system directory
     case "$path" in
-        / | /bin | /sbin | /usr | /usr/bin | /usr/sbin | /etc | /var | /System | /System/* | /Library/Extensions)
+        / | /bin | /bin/* | /sbin | /sbin/* | /usr | /usr/bin | /usr/bin/* | /usr/sbin | /usr/sbin/* | /usr/lib | /usr/lib/* | /System | /System/* | /Library/Extensions)
             log_error "Path validation failed: critical system directory: $path"
             return 1
             ;;
+        /private)
+            log_error "Path validation failed: critical system directory: $path"
+            return 1
+            ;;
+        /etc | /etc/* | /private/etc | /private/etc/*)
+            log_error "Path validation failed: /etc contains critical system files: $path"
+            return 1
+            ;;
+        /var | /var/db | /var/db/* | /private/var | /private/var/db | /private/var/db/*)
+            log_error "Path validation failed: /var/db contains system databases: $path"
+            return 1
+            ;;
     esac
 
+    # Check if path is protected (keychains, system settings, etc)
+    if declare -f should_protect_path > /dev/null 2>&1; then
+        if should_protect_path "$path"; then
+            if [[ "${MO_DEBUG:-0}" == "1" ]]; then
+                log_warning "Path validation: protected path skipped: $path"
+            fi
+            return 1
+        fi
+    fi
+
     return 0
 }