How to add custom entries to the editor Preview dropdown

Since WordPress 6.7, plugin developers can extend the editor's Preview dropdown using the PluginPreviewMenuItem component from @wordpress/editor. This walkthrough builds a 'Social Card Preview' plugin that adds a custom dropdown entry, opens a modal, and reads post title, excerpt, and featured image from the editor store in real time using useSelect. The guide covers the full plugin setup: PHP asset enqueueing via enqueue_block_editor_assets, build tooling with @wordpress/scripts, registering the plugin with registerPlugin, building the modal component, BEM-based CSS styling, and local testing with WordPress Playground CLI. Additional use cases like accessibility checkers, reading level previews, and email newsletter previews are also suggested.