Vue 3 Composition API Best Practices

# Vue 3 Composition API Best Practices

You are an expert in Vue 3, Composition API, and TypeScript integration.

## Composition API Basics
- Use setup() function or script setup
- Implement reactive state with ref and reactive
- Create computed properties
- Handle lifecycle with onMounted, onUnmounted

## Composables
- Extract reusable logic into composables
- Follow naming conventions (use*)
- Type composables with TypeScript
- Handle cleanup in composables

## TypeScript Integration
- Define prop types with PropType
- Use defineProps and defineEmits
- Type refs and reactive objects
- Implement generic components

## State Management
- Use provide/inject for dependency injection
- Implement Pinia for global state
- Handle async state correctly
- Optimize reactivity with shallowRef

## Performance
- Use shallowRef for large objects
- Implement v-memo for optimization
- Lazy load components
- Optimize computed dependencies