fix(builder): un-hide and relabel static-page content editor, warn on publish/remove-language

- KNOWN-ISSUES item 11: the WYSIWYG page content editor was buried inside
  a collapsed Advanced <details>, labeled 'Raw HTML (advanced)'. Moved it
  to the top of the Content tab, unwrapped, relabeled 'Page Content' /
  'Содержимое страницы' / 'Эջի բովանդակություն' with a plain-language
  description. Advanced tab keeps genuinely technical fields (id, slug,
  route, custom template).
- Publish (save-bar) and Remove language (languages-section) had no
  confirmation despite being destructive/high-impact — added
  window.confirm guards using the existing builder.confirm* i18n pattern
  (matches resetDraft/resetSection/dirty-guard precedent), all 3 locales.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/i18n/en.ts

@@ -574,6 +574,8 @@ export const en: Translations = {
     save: 'Save',
     publish: 'Publish',
     confirmLeaveUnsaved: 'You have unsaved changes. Leave anyway?',
+    confirmPublish: 'This makes your current changes live on the storefront immediately, replacing what shoppers see now. Continue?',
+    confirmRemoveLanguage: 'This removes the language and any content translated into it. Shoppers using this language will see the default language instead. Continue?',
     promptLinkUrl: 'URL',
     promptImageUrl: 'Image URL',
     promptEmbedUrl: 'Embed URL',
@@ -1040,6 +1042,8 @@ export const en: Translations = {
     groupSharing: 'Sharing',
     groupAdvanced: 'Advanced',
     groupAdvancedHtml: 'Raw HTML (advanced)',
+    pageContentLabel: 'Page Content',
+    pageContentDesc: 'Write and format the text, images, and links shoppers will see on this page.',
     seoExplainDesc: 'This is what shows up in search results — a clear title and description help customers find this page.',
     seoTitleHelp: 'The headline shown in search results. Keep it short and descriptive.',
     seoDescriptionHelp: 'A short summary shown under the title in search results.',