feat: migrate from ActiveSupport::Autoload to Zeitwerk

[seuros]

the autoloader is acting in a non predictable manner when i try to implement this gem, with my new gem.
with error : NameError: uninitialized constant ClosureTree::HasClosureTree::ClosureTree

Switching to Zeitwerk fixes this problem.

Removed non-op configuration and deprecated the configuration mechanism.

[Copilot]

Pull Request Overview

This PR migrates the gem from ActiveSupport::Autoload to Zeitwerk for module loading to resolve autoloading issues. The change aims to fix NameError: uninitialized constant ClosureTree::HasClosureTree::ClosureTree errors when using this gem with other gems.

• Replaces ActiveSupport::Autoload with Zeitwerk loader configuration
• Removes the configuration system (Configuration class and related generator)
• Deprecates the ClosureTree.configure method with a warning message

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
lib/closure_tree.rb	Core migration from ActiveSupport::Autoload to Zeitwerk, removes adapter loading hooks
closure_tree.gemspec	Adds zeitwerk dependency
lib/closure_tree/configuration.rb	Removes Configuration class entirely
lib/closure_tree/has_closure_tree.rb	Removes database_less configuration check in error handling
lib/closure_tree/support.rb	Removes manual require statements for autoloaded modules
lib/closure_tree/adapter_support.rb	Removes AdapterSupport module
lib/generators/closure_tree/config_generator.rb	Removes config generator
lib/generators/closure_tree/templates/config.rb	Removes config template

[Copilot]

Creating a new ActiveSupport::Deprecation instance for each call is inefficient. Consider using ActiveSupport::Deprecation.warn directly or creating a shared deprecation instance.

Suggested change

	ActiveSupport::Deprecation.new.warn(
	ActiveSupport::Deprecation.warn(

[Copilot]

The context should be ActiveRecord::Base not the block scope. This line should be ActiveRecord::Base.extend ClosureTree::HasClosureTree, ClosureTree::HasClosureTreeRoot to properly extend ActiveRecord::Base with the modules.

Suggested change

	ActiveSupport.on_load(:active_record) do
	extend ClosureTree::HasClosureTree, ClosureTree::HasClosureTreeRoot
	end
	ActiveRecord::Base.extend ClosureTree::HasClosureTree, ClosureTree::HasClosureTreeRoot