feat(home): add compact home page preset to avoid abuse classification

- Add compact_home_enabled setting to provide a minimal landing page
- Preserves custom home_content priority over compact mode
- Renders only site identity, navigation, and login/dashboard link
- Avoids marketing copy that triggers anti-fraud systems
- Includes focused backend/frontend tests and i18n support

Fixes #5065

frontend/src/types/index.ts

@@ -210,6 +210,7 @@ export interface PublicSettings {
   contact_info: string
   doc_url: string
   home_content: string
+  compact_home_enabled: boolean
   hide_ccs_import_button: boolean
   payment_enabled: boolean
   risk_control_enabled: boolean