- Refactored WPALLSTARS_Settings_Manager to use the standard WordPress Settings API.
- Stores all settings in a single 'wpallstars_options' array.
- Implemented register_setting, sections, fields, render callbacks, and sanitization.
- Updated display_general_tab and display_advanced_tab to use settings_fields() and do_settings_sections().
- Adjusted WPALLSTARS_Admin_Manager to initialize the refactored settings manager.
- Kept original menu structure (add_options_page) and file names for stability.
- Temporarily removed AJAX instant-save functionality.