Refactor(Admin): Implement Settings API & AJAX save for Settings Manager

- Refactored WPALLSTARS_Settings_Manager to use WordPress Settings API.
- Stores settings in single 'wpallstars_options' array.
- Implemented robust AJAX saving for specific settings (e.g., color scheme, auto-upload) via WPALLSTARS_Admin_Manager::update_option.
- Updated JS and setting render functions for AJAX.
- Corrected admin menu registration and script enqueue hooks.
- Includes file renames from wp-allstars to wpallstars.

includes/class-wp-allstars-sync-guard.php

@@ -1,60 +0,0 @@
-<?php
-/**
- * WP ALLSTARS Sync Guard
- *
- * Prevents plugin loading during sync operations to avoid fatal errors.
- *
- * @package WP_ALLSTARS
- * @since 0.2.3.1
- */
-
-if (!defined('ABSPATH')) {
-    exit;
-}
-
-/**
- * Class responsible for detecting sync operations and preventing plugin loading
- */
-class WP_Allstars_Sync_Guard {
-
-    /**
-     * Flag file name for sync operations
-     */
-    const SYNC_FLAG_FILE = '.syncing';
-
-    /**
-     * Check if sync is in progress
-     *
-     * @return bool Whether sync is in progress
-     */
-    public static function is_sync_in_progress() {
-        $flag_file = plugin_dir_path(dirname(__FILE__)) . self::SYNC_FLAG_FILE;
-        return file_exists($flag_file);
-    }
-
-    /**
-     * Handle sync mode by showing admin notice and preventing plugin loading
-     *
-     * @return bool True if sync is in progress, false otherwise
-     */
-    public static function handle_sync_mode() {
-        if (self::is_sync_in_progress()) {
-            // Add admin notice
-            add_action('admin_notices', array(__CLASS__, 'display_sync_notice'));
-            
-            // Return true to indicate plugin should not continue loading
-            return true;
-        }
-        
-        return false;
-    }
-    
-    /**
-     * Display sync in progress notice
-     */
-    public static function display_sync_notice() {
-        echo '<div class="notice notice-warning is-dismissible">';
-        echo '<p><strong>WP Allstars:</strong> Plugin files are currently syncing. The plugin functionality is temporarily disabled to prevent errors. Please try again in a moment.</p>';
-        echo '</div>';
-    }
-}