refactor(webapp): remove emoji web app logo option

Drop the emoji-logo feature (and its font picker) from the Web App. Only
an uploaded/linked image logo and favicon remain; when no logo is set,
the default project logo is shown. Existing emoji-logo overrides are
ignored — the keys are gone from the manifest, so the override service
skips them and the app falls back to the default logo.

- Remove WEBAPP_LOGO_USE_EMOJI / WEBAPP_LOGO_EMOJI / WEBAPP_LOGO_EMOJI_FONT
  settings, validators, manifest entries and override/runtime plumbing.
- Strip the animated-emoji fetch/cache subsystem, the /webapp-emoji route
  and emoji branches from logo/favicon resolution; leftover emoji cache
  files are now purged on appearance save.
- Simplify BrandMark to an image-only component and drop the emoji UI
  from the admin Appearance section.
- Regenerate the demo settings manifest and clean docs, locales, nginx
  and demo data of emoji-logo references.

locales/ru.json

@@ -1574,20 +1574,7 @@
   "admin_settings_field_subscription_mini_app_url_label": "Публичный URL Mini App",
   "admin_settings_field_subscription_mini_app_url_description": "Например, https://app.example.com/.",
   "admin_settings_field_webapp_primary_color_label": "Основной цвет",
-  "admin_settings_field_webapp_logo_use_emoji_label": "Использовать эмоджи-логотип",
   "admin_settings_field_webapp_logo_url_label": "URL логотипа",
-  "admin_settings_field_webapp_logo_emoji_label": "Эмоджи-логотип",
-  "admin_settings_field_webapp_logo_emoji_font_label": "Шрифт эмоджи-логотипа",
-  "admin_settings_field_webapp_logo_emoji_font_description": "Выберите шрифт для отображения эмодзи-логотипа.",
-  "admin_settings_field_webapp_logo_emoji_font_choice_system": "Системный (по умолчанию)",
-  "admin_settings_field_webapp_logo_emoji_font_choice_noto_color": "Noto Color Emoji",
-  "admin_settings_field_webapp_logo_emoji_font_choice_noto_color_animated": "Noto Color Emoji Animated",
-  "admin_settings_field_webapp_logo_emoji_font_choice_noto_emoji": "Noto Emoji",
-  "admin_settings_field_webapp_logo_emoji_font_choice_twemoji": "Twitter Emoji",
-  "admin_settings_field_webapp_logo_emoji_font_choice_openmoji": "OpenMoji",
-  "admin_settings_field_webapp_logo_emoji_font_choice_apple": "Apple Color Emoji (local)",
-  "admin_settings_field_webapp_logo_emoji_font_choice_segoe": "Segoe UI Emoji (local)",
-  "admin_settings_field_webapp_logo_emoji_font_choice_noto_local": "Noto Emoji (local)",
   "admin_settings_field_webapp_favicon_use_custom_label": "Использовать отдельную favicon",
   "admin_settings_field_webapp_favicon_url_label": "URL отдельной favicon",
   "admin_settings_field_webapp_logo_favicon_url_label": "Favicon из логотипа",
@@ -1962,9 +1949,8 @@
   "admin_actions": "Действия",
   "admin_ad_created": "Кампания создана",
   "admin_ad_deleted": "Кампания удалена",
-  "admin_appearance_brand_sub": "Файл, ссылка или подтвержденный emoji-логотип",
+  "admin_appearance_brand_sub": "Загрузите логотип файлом или по ссылке",
   "admin_appearance_brand_title": "Логотип",
-  "admin_appearance_emoji_font": "Шрифт emoji",
   "admin_appearance_favicon_upload_failed": "Не удалось загрузить favicon",
   "admin_appearance_favicon_upload_file": "Загрузить favicon",
   "admin_appearance_favicon_upload_url": "По ссылке",
@@ -1980,7 +1966,6 @@
   "admin_appearance_themes_sub": "Глобальная тема, accent color и предпросмотр",
   "admin_appearance_themes_title": "Темы",
   "admin_appearance_use_custom_favicon": "Использовать отдельную favicon",
-  "admin_appearance_use_emoji_logo": "Использовать emoji-логотип",
   "admin_backups_create": "Создать бэкап",
   "admin_backups_create_done": "Бэкап создан",
   "admin_backups_create_failed": "Не удалось создать бэкап",