Implement version 0.0.8 features

- Remove Current Version field from product license settings
- Derive current version from latest product version in database
- Refactor email system to use WooCommerce email notification classes
- Add LicenseExpirationEmail WC_Email class for expiration warnings
- Add customizable email templates (HTML and plain text)
- Update settings to link to WooCommerce email configuration
- Update translations for new email-related strings

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/Admin/VersionAdminController.php

@@ -263,9 +263,6 @@ final class VersionAdminController
             wp_send_json_error(['message' => __('Failed to create version.', 'wc-licensed-product')]);
         }
 
-        // Also update the product's current version meta
-        update_post_meta($productId, '_licensed_current_version', $version);
-
         wp_send_json_success([
             'message' => __('Version added successfully.', 'wc-licensed-product'),
             'version' => $newVersion->toArray(),