Combining Types

1. Create base types with these runtime field types:
   • WithId — id (string)
   • WithTimestamps — createdAt and updatedAt (Date)
   • WithAuthor — authorId and authorName (string)
2. Build entity types by intersecting those bases (and adding entity-specific fields):
   • User — id + timestamps, plus name and email (string)
   • Post — id + timestamps + author, plus title and content (string)
   • Comment — id + timestamps + author, plus text and postId (string)
3. Create sample user, post, and comment values and export them by name

Completion criteria

• Named exports: user, post, comment
• user has string id / name / email and Date createdAt / updatedAt
• post / comment also include author fields (authorId, authorName) and their own content fields (title/content or text/postId)