positioning

Handles global, simple, and complex scopes including polymorphic associations, as shown in the `positioned` method examples with arrays like [:list, :category, :enabled].

Automatically maintains sequential integer positions without gaps, with a built-in `heal_position_column!` method to fix existing data, ensuring clean list ordering.

Uses row locking to prevent race conditions during updates, as mentioned in the concurrency section, making it reliable for multi-user environments.

Supports moving items with `before:` or `after:` references instead of manual integer assignments, simplifying list manipulations in code.

Provides `Positioning::RelativePosition` Struct for easy form integration, allowing relative positioning via Rails form helpers as detailed in the form examples.