go-vikunja/app ? reverse-engineered prompt

Build me a cross platform mobile and web app for Vikunja, the open source to do app.

I want users to be able to sign in to their Vikunja server or Vikunja Cloud, then manage tasks in a clean and simple way. The app should let people view their work in the different ways Vikunja supports, like a plain list, kanban style boards, tables, and a timeline or gantt style view. It should feel good on Android, iPhone, and web, and keep the focus on privacy and self hosted data.

Please include the main basics someone would expect from a task app, like creating and editing tasks, organizing them, collaborating with teams, and moving between views easily. If anything needs current setup details, look up the latest docs online and make sensible choices. Keep it polished, modern, and ready to run as a real app, even if some parts need to stay simple for now.