Build a custom Gutenberg sidebar plugin document panel

I need a custom panel in the post editor sidebar labeled "SEO Priority" with a select
field (Low / Medium / High) that saves to post meta, visible alongside the built-in
Featured Image and Categories panels.

ENVIRONMENT: [WordPress 6.7, block editor only (no classic editor fallback needed),
registered from a plugin, needs to work for both `post` and `page` post types]

Build this like a developer who's shipped editor sidebar panels before, in order:
1. Show the PHP side first, since it's the part most people get wrong: register the
   meta field with `register_post_meta()` on `init`, with `show_in_rest => true` (a
   panel that isn't exposed via REST simply won't show any data or save anything, with
   no error in the console, just silent failure), a defined `type`, `single => true`,
   and an explicit `auth_callback` checking `current_user_can( 'edit_post', $post_id )`
   rather than leaving the default (which restricts to users who can `edit_posts` in
   general, not necessarily this specific post).
2. Show the JS side: `registerPlugin()` wrapping a `PluginDocumentSettingPanel`
   component, with a `SelectControl` bound via `useEntityProp( 'postType', postType,
   'meta' )` so it reads and writes through the same data layer the rest of the editor
   uses, rather than a separate `useState` that would fall out of sync with actual
   save state.
3. Set `icon` and `name` properties on the panel appropriately, and explain the
   `PluginDocumentSettingPanel`'s optional `className` prop for consistent styling with
   core panels rather than an ad hoc custom style.
4. Flag the edge case that causes "my panel doesn't show up at all": if the plugin's
   editor script isn't enqueued with the correct dependencies
   (`wp-plugins`, `wp-edit-post`, `wp-editor`, `wp-components`, `wp-data`) via
   `wp_enqueue_script()` on `enqueue_block_editor_assets`, the panel registration
   either silently no-ops or throws a console error about an undefined component,
   depending on which dependency is missing.
5. Confirm the panel works identically for both `post` and `page`: since
   `useEntityProp`'s `postType` argument needs to come from `wp.data.select('core/editor').getCurrentPostType()`
   rather than being hardcoded to `'post'`, or the panel will silently fail to save
   meta when used on a page.

Replace the panel label, field type, and post types with your actual needs.