i18n: internationalize all admin pages

Add full i18n coverage for the admin section — locale keys, layout nav,
users, videos, and articles pages (list, new, edit).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/frontend/src/lib/i18n/locales/en.ts

@@ -896,6 +896,142 @@ export default {
   head: {
     title: "SexyArt | {title}",
   },
+  admin: {
+    nav: {
+      back_to_site: "← Back to site",
+      back_mobile: "← Back",
+      title: "Admin",
+      users: "Users",
+      videos: "Videos",
+      articles: "Articles",
+    },
+    common: {
+      save_changes: "Save changes",
+      saving: "Saving…",
+      creating: "Creating…",
+      deleting: "Deleting…",
+      featured: "Featured",
+      premium: "Premium",
+      write: "Write",
+      preview: "Preview",
+      cover_image: "Cover image",
+      tags: "Tags",
+      publish_date: "Publish date",
+      title_field: "Title *",
+      slug_field: "Slug *",
+      title_slug_required: "Title and slug are required",
+      image_uploaded: "Image uploaded",
+      image_upload_failed: "Image upload failed",
+    },
+    users: {
+      title: "Users",
+      total: "{total} total",
+      search_placeholder: "Search email or name…",
+      filter_all: "All",
+      col_user: "User",
+      col_email: "Email",
+      col_role: "Role",
+      col_joined: "Joined",
+      col_actions: "Actions",
+      role_viewer: "Viewer",
+      role_model: "Model",
+      admin_badge: "Admin",
+      no_results: "No users found",
+      showing: "Showing {start}–{end} of {total}",
+      role_updated: "Role updated to {role}",
+      role_update_failed: "Failed to update role",
+      delete_title: "Delete user",
+      delete_description: "Are you sure you want to permanently delete {name}? This cannot be undone.",
+      delete_success: "User deleted",
+      delete_error: "Failed to delete user",
+    },
+    user_edit: {
+      first_name: "First name",
+      last_name: "Last name",
+      artist_name: "Artist name",
+      avatar: "Avatar",
+      banner: "Banner",
+      is_admin: "Administrator",
+      is_admin_hint: "Grants full admin access to the dashboard",
+      photos: "Photo gallery",
+      no_photos: "No photos yet.",
+      avatar_uploaded: "Avatar uploaded",
+      avatar_failed: "Avatar upload failed",
+      banner_uploaded: "Banner uploaded",
+      banner_failed: "Banner upload failed",
+      photos_added: "{count} photos added",
+      photo_upload_failed: "Failed to upload {name}",
+      photo_remove_failed: "Failed to remove photo",
+      save_success: "Saved",
+      save_error: "Save failed",
+    },
+    videos: {
+      title: "Videos",
+      new_video: "New video",
+      col_video: "Video",
+      col_badges: "Badges",
+      col_plays: "Plays",
+      col_likes: "Likes",
+      no_results: "No videos yet",
+      delete_title: "Delete video",
+      delete_description: "Permanently delete {title}? This cannot be undone.",
+      delete_success: "Video deleted",
+      delete_error: "Failed to delete video",
+    },
+    video_form: {
+      new_title: "New video",
+      edit_title: "Edit video",
+      title_placeholder: "Video title",
+      slug_placeholder: "video-slug",
+      description: "Description",
+      description_placeholder: "Optional description",
+      video_file: "Video file",
+      current_file: "Current file: {id}",
+      models: "Models",
+      no_models: "No models",
+      models_selected: "{count} models selected",
+      cover_uploaded: "Cover image uploaded",
+      video_uploaded: "Video uploaded",
+      video_upload_failed: "Video upload failed",
+      create_success: "Video created",
+      create_error: "Failed to create video",
+      update_success: "Video updated",
+      update_error: "Failed to update video",
+      create: "Create video",
+    },
+    articles: {
+      title: "Articles",
+      new_article: "New article",
+      col_article: "Article",
+      col_category: "Category",
+      col_published: "Published",
+      no_results: "No articles yet",
+      delete_title: "Delete article",
+      delete_description: "Permanently delete {title}? This cannot be undone.",
+      delete_success: "Article deleted",
+      delete_error: "Failed to delete article",
+    },
+    article_form: {
+      new_title: "New article",
+      edit_title: "Edit article",
+      title_placeholder: "Article title",
+      slug_placeholder: "article-slug",
+      excerpt: "Excerpt",
+      excerpt_placeholder: "Short summary…",
+      content: "Content (Markdown)",
+      content_placeholder: "Write in Markdown…",
+      preview_placeholder: "Preview will appear here…",
+      category: "Category",
+      category_placeholder: "e.g. news, tutorial…",
+      author: "Author",
+      no_author: "No author",
+      create_success: "Article created",
+      create_error: "Failed to create article",
+      update_success: "Article updated",
+      update_error: "Failed to update article",
+      create: "Create article",
+    },
+  },
   gamification: {
     leaderboard: "Leaderboard",
     leaderboard_description: "Compete with other creators and players for the top spot",