Challenge 1: Wire Up Post and Comment — Solution

# app/models/post.rb
class Post < ApplicationRecord
  has_many :comments
end

# app/models/comment.rb
class Comment < ApplicationRecord
  belongs_to :post
end

# Demonstrating each direction:
@post.comments        # => all Comment records where post_id = @post.id
@comment.post          # => the single Post this comment belongs to

=begin
Notes:
- has_many :comments on Post and belongs_to :post on Comment are two
  halves of the same relationship -- both are needed for both directions
  (@post.comments and @comment.post) to work.
- This relies entirely on the post_id column already created by Chapter
  5's migration; belongs_to :post specifically expects a column named
  post_id (the singular association name + _id) by convention, with no
  extra configuration needed since the column already matches.
- @post.comments returns a chainable relation (per Chapter 5), not a
  plain array -- you could continue with @post.comments.where(...) or
  @post.comments.order(...) exactly as shown in the chapter.
=end