chore: complete M1.1 runtime QA and release packaging

shop/docs/COMPATIBILITY.md

@@ -0,0 +1,46 @@
+# XShop – Compatibility
+
+## 1. Tested Up To
+
+| Dependency | Minimum | Tested |
+|------------|---------|--------|
+| WordPress  | 6.4     | 6.6.x  |
+| WooCommerce| 8.0     | 9.x    |
+| PHP        | 8.2     | 8.2, 8.3 |
+| Elementor  | 3.15 (optional) | 3.2x |
+| Gutenberg  | WP bundled | — |
+| Browsers   | last 2 versions: Chrome, Firefox, Edge, Safari | — |
+
+## 2. WordPress APIs Used
+
+- Theme support: `add_theme_support('title-tag','post-thumbnails','html5','custom-logo','woocommerce'...)`
+- Menus/sidebars/widgets: `register_nav_menus`, `register_sidebar`, `widgets_init`.
+- Settings: `register_setting` + single option `xshop_settings` (Settings API).
+- Customizer: `customize_register` for preview (typography/colours).
+- REST: `register_rest_route` (namespace `xshop/v1`).
+
+## 3. WooCommerce Integration
+
+- Declared `add_theme_support('woocommerce')` + gallery features (`wc-product-gallery-zoom/lightbox/slider`).
+- Wrapper via `woocommerce_before_main_content` / `after_main_content`.
+- Hooks over template overrides. Overrides documented in `docs/woocommerce.md` with WC version map; monitor `WC()->version` and template `Version:` header.
+
+## 4. HPOS
+
+- Uses `wc_get_products` CRUD, not direct post table writes. Compatible with High-Performance Order Storage. No direct `wp_posts` manipulation for orders.
+
+## 5. Elementor
+
+- Widgets registered via `\Elementor\Plugin::instance()->widgets_manager->register` if Elementor active. Namespaced `XShop\Core\Elementor\Widgets\*`. No hard dependency – `is_plugin_active` guard.
+
+## 6. Gutenberg
+
+- Block styles via `register_block_style`, theme.json opt-in later. No classic-editor dependency.
+
+## 7. Multisite
+
+- Not primary target; options are per-site (no network options in v1).
+
+## 8. Upgrade Notes
+
+- Template version bumps checked via `WC template version` comment. Override only where necessary; changelog notes any override update.