Agent Skills: active-record-associations

Expert guidance for defining and using Active Record associations in Rails. Use when creating associations, defining model relationships, troubleshooting foreign keys, fixing N+1 queries, setting up belongs_to, has_many, has_one, has_many :through, polymorphic associations, self-referential joins, join tables, counter caches, dependent options, inverse_of, eager loading, or any question about how models relate to each other.