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.

docs/getting-started/configuration.md

@@ -87,7 +87,7 @@ openssl rand -hex 32
 Перед первым запуском создайте каталоги и отдайте их пользователю контейнера:
 
 ```bash
-mkdir -p data/themes data/webapp-logo data/webapp-emoji data/tariffs
+mkdir -p data/themes data/webapp-logo data/tariffs
 touch data/locales-overrides.json
 chown -R 10001:10001 data
 chmod -R u+rwX data

docs/getting-started/deployment.md

@@ -377,7 +377,7 @@ distributed lock; код подготовлен к нескольким репл
 Перед первым запуском на сервере заранее дайте права пользователю контейнера `10001`:
 
 ```bash
-mkdir -p data/themes data/webapp-logo data/webapp-emoji data/tariffs
+mkdir -p data/themes data/webapp-logo data/tariffs
 touch data/locales-overrides.json
 chown -R 10001:10001 data
 chmod -R u+rwX data