Migrate to Euro-Office and refresh the editor home experience.

Swap Document Server to Euro-Office, add blank-document creation, and restyle the app with an Office-like light/dark theme and compact editor toolbar.

Co-authored-by: Cursor <cursoragent@cursor.com>

.env.example

@@ -1,11 +1,11 @@
-# Shared JWT secret (must match OnlyOffice Document Server)
+# Shared JWT secret (must match Euro-Office Document Server)
 JWT_SECRET=change-me-to-a-long-random-secret
 
 # URLs
 PUBLIC_URL=http://localhost:3000
 INTERNAL_URL=http://backend:3000
 ONLYOFFICE_URL=http://localhost:8080
-ONLYOFFICE_INTERNAL_URL=http://onlyoffice
+ONLYOFFICE_INTERNAL_URL=http://documentserver
 
 # Session
 SESSION_TTL_MS=900000