feat(17-04): menu plugin admin with registry types, URL checks and tree reorder

- golem15.menu plugin, tables golem15_menu_menus and golem15_menu_menu_entries with the PHP columns plus a nullable url_pattern (D-02)
- MenuEntry BeforeSave ports PHP beforeSave: nest columns 0, menu from the parent, sort_order after the menu's last
- entry type dropdown: url, divider and the signpost registry types; reference depends on type through signpost.ReferenceOptions
- URL scheme allowlist (errors.url_scheme), target _self or _blank, menu and parent cycle checks
- menu filter, toolbar reorder/create/delete and config_reorder.yaml partitioned by menu
- navigation Menus with Menus and Menu entries, permission golem15.menu.manage_menu, en and pl phrasebooks
- TestMenuAdminSmoke

lang/en/lang.yaml

@@ -0,0 +1,47 @@
+plugin:
+  name: Menus
+  description: Site menus with links, dividers and content entries.
+permissions:
+  manage_menu: Manage site menus
+models:
+  general:
+    id: ID
+    created_at: Created At
+    updated_at: Updated At
+  menu:
+    label: Menu
+    label_plural: Menus
+    name: Name
+    code: Code
+    css_class: CSS class
+    is_active: Active
+  menuentry:
+    label: Menu entry
+    label_plural: Menu entries
+    menu: Menu
+    menu_comment: Entries with a parent belong to the parent's menu.
+    parent: Parent
+    type: Type
+    type_url: Link
+    type_divider: Divider
+    title: Title
+    url: URL
+    url_comment: Used by Link entries. Start with http://, https://, mailto:, tel:, / or #.
+    reference: Reference
+    reference_comment: The record this entry points to, for types that need one.
+    url_pattern: URL pattern
+    url_pattern_comment: Use :placeholder syntax, e.g. /blog/:slug
+    code: Code
+    icon: Icon
+    css_class: CSS class
+    target: Opens in
+    target_self: Same tab
+    target_blank: New tab
+    is_published: Published
+    reorder_title: Reorder menu entries
+errors:
+  url_scheme: Use a link that starts with http://, https://, mailto:, tel:, / or #.
+  target: Choose Same tab or New tab.
+  type_unknown: Choose one of the listed types.
+  menu_required: Choose a menu or a parent entry.
+  parent_cycle: An entry cannot be placed under itself or one of its own entries.