Use version placeholder for auto-deployment

Replace hardcoded version with {auto_update_value_on_deploy} placeholder that gets replaced during the Gitea workflow build process.

Changes:
- Updated Version comment to use placeholder
- Updated TWP_VERSION constant to use placeholder
- Modified release workflow to replace both instances of the placeholder

This matches the pattern used in the fourthwall plugin and ensures the version is automatically set during the release build process.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

twilio-wp-plugin.php

@@ -3,7 +3,7 @@
  * Plugin Name: Twilio WP Plugin
  * Plugin URI: https://repo.anhonesthost.net/wp-plugins/twilio-wp-plugin
  * Description: WordPress plugin for Twilio integration with phone scheduling, call forwarding, queue management, and Eleven Labs TTS
- * Version: 2.8.9
+ * Version: {auto_update_value_on_deploy}
  * Author: Josh Knapp
  * License: GPL v2 or later
  * Text Domain: twilio-wp-plugin
@@ -15,7 +15,7 @@ if (!defined('WPINC')) {
 }
 
 // Plugin constants
-define('TWP_VERSION', '2.8.9');
+define('TWP_VERSION', '{auto_update_value_on_deploy}');
 define('TWP_DB_VERSION', '1.6.2'); // Track database version separately
 define('TWP_PLUGIN_DIR', plugin_dir_path(__FILE__));
 define('TWP_PLUGIN_URL', plugin_dir_url(__FILE__));