feat: infinite scroll calendar demo with drag-and-drop between days

[simbo1905]

Description

This PR implements a complete infinite scroll calendar with event cards and drag-and-drop functionality.

Key Features Added

📅 Calendar System

• UK week numbering system (ISO 8601) starting Mondays
• Current week initialization (e.g. Week 41, Oct 6-12, 2025)
• Infinite scroll loading for additional weeks
• Year display in week headers

🎯 Drag & Drop Functionality

• Full drag-and-drop support between calendar days using
• Cross-day meal transfers with proper state management
• Visual feedback with drop zone highlighting during drag operations
• Smooth animations using Svelte's flip animation

🍽️ Rich Meal Cards

• Beautiful meal cards with icons, time displays, and color-coded borders
• Proper ARIA attributes for accessibility
• Responsive design with scroll snapping
• Support for different meal types (utensils, chef-hat icons)

🎨 User Interface

• Interactive meal selection modal with search functionality
• Removed unnecessary UI elements (header banner, ingredient button)
• Enhanced drop zones to include empty state areas
• Mobile-friendly responsive layout

Technical Implementation

Dependencies

• Added for drag-and-drop functionality
• Maintained Svelte 5 compatibility with runes system

Type Safety

• Updated TypeScript interfaces with unique card IDs
• Added proper drag-and-drop event types
• Full type safety across all components

State Management

• Implemented cross-day transfer logic
• Proper reactive state updates using Svelte 5 runes
• Maintained data integrity during drag operations

UI/UX Improvements

• Better Targeting: Drop zones now include the '+ Add' button area for easier targeting of empty days
• Visual Feedback: Enhanced drop zone styling with blue outline and background highlighting

Testing

All functionality has been tested and verified:

• ✅ Drag meals between days with existing meals
• ✅ Drag meals into empty days (now works properly)
• ✅ Meal selection and addition via modal
• ✅ Search functionality in modal
• ✅ Responsive design across screen sizes
• ✅ TypeScript compilation without errors

The implementation provides a complete infinite scrolling calendar experience while maintaining the lightweight Svelte 5 architecture and following existing code patterns.

[vercel]

@simbo1905 is attempting to deploy a commit to the domino Team on Vercel.

A member of the Team first needs to authorize it.

[ndom91]

Hey so thanks for your interest! I appreciate a demo, but i don't know if this is the right place for it.

If you can make it self-contained in a sub folder like my primary development example sort of, that would be acceptable.

However, do not add dependencies like tailwind to the main package, that doesn't make much sense.

Thanks!