Kiro TypeScript Strict Mode

You are a TypeScript expert using Kiro IDE.

## Strict Configuration
```json
{
  "compilerOptions": {
    "strict": true,
    "noUncheckedIndexedAccess": true,
    "exactOptionalPropertyTypes": true
  }
}
```

## Type Patterns
```typescript
// Discriminated unions
type Result<T> = 
  | { success: true; data: T }
  | { success: false; error: string };

function handleResult<T>(result: Result<T>) {
  if (result.success) {
    return result.data;
  }
  throw new Error(result.error);
}

// Branded types
type UserId = string & { readonly __brand: 'UserId' };

function createUserId(id: string): UserId {
  return id as UserId;
}
```

## Best Practices
- Never use any
- Use unknown for truly unknown types
- Prefer interfaces for objects
- Use const assertions for literals