Off Day

Create an iOS application called "Off Day" that helps users classify days as work or off days. The app needs a core logic engine that determines the day type based on a fixed priority: User Mark > Public Holiday Template > Base Calendar. I need support for managing multiple built-in public holiday templates for regions like China Mainland, US, Japan, etc., and allow users to create, edit, and import/export custom holiday plans using JSON. Key features must include rich App Intents for Shortcuts automation (like checking day type or finding the next off day), and a notification center for upcoming holidays or template expirations. Since it's local-first, please incorporate local storage for user overrides and optional iCloud backup.