Implement Tag System with Unique IDs

[DrunkOnJava]

🏷️ Complete Tag System Implementation

Current State

• Tags stored as simple strings in Item model
• TODOs in ItemsListViewModel indicate tag IDs not implemented
• No tag management UI or persistence

Required Implementation

1. Tag Model and Repository

   • Create Tag entity with id, name, color
   • Implement TagRepository with CRUD operations
   • Add tag-to-item relationship management

2. UI Components

   • Tag picker/selector component
   • Tag management view (create, edit, delete)
   • Tag autocomplete in item edit view
   • Tag color customization

3. Integration

   • Update Item model to use tag IDs
   • Migrate existing string tags to Tag entities
   • Update filtering to work with tag IDs

Database Schema

struct Tag {
    let id: UUID
    let name: String
    let color: String // Hex color
    let createdAt: Date
}

Acceptance Criteria

• Tags have unique IDs and properties
• Tag management UI is intuitive
• Existing tags migrated successfully
• Tag filtering works correctly

Parent Epic

Related to #86 (Core Data Persistence)

[DrunkOnJava]

Closing: This issue has been resolved/superseded by the complete modular architecture restructure now in main branch (commit 33a0ead). The new architecture implements a comprehensive solution that addresses the core needs this issue was tracking.