refactor(builder): single language manager, theme before branding

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

P0 user feedback: General asked admins to type locale codes comma-separated, and Branding (logos) came before Theme (colors).

- Root cause: General duplicated language management as raw text/CSV inputs while a full Languages manager section (add/remove/set-default with per-locale content seeding) already existed one tab away. Removed the duplicate inputs; General now shows a read-only chip summary (default language first, marked) with a 'Manage languages' link to the real manager. One source of truth, no comma parsing, no risk of bypassing LocaleSyncService
- Builder navigation now orders Theme before Branding - merchants pick a palette first, then upload logos that match it
- New builder keys (languagesSummaryDesc, manageLanguages) in en/ru/hy; verified in browser (chips RU-default/EN/HY, nav order theme->branding)

src/app/i18n/en.ts

@@ -687,6 +687,8 @@ export const en: Translations = {
     linkVisibleDesc: 'Whether this navigation link is shown to shoppers.',
     appName: 'Marketplace Builder',
     backToDashboard: 'Back to dashboard',
+    languagesSummaryDesc: 'Languages your marketplace is available in. The first one is what customers see by default.',
+    manageLanguages: 'Manage languages',
     htmlToolBold: 'Bold',
     htmlToolItalic: 'Italic',
     htmlToolUnderline: 'Underline',