### Add i18n-debug Gem to Gemfile (Ruby)

Source: https://github.com/fphilipe/i18n-debug/blob/master/README.md

Adds the `i18n-debug` gem to the project's `Gemfile`. It is typically placed within the `:development` group to ensure it's only available during development, avoiding unnecessary dependencies in production.

```Ruby
gem 'i18n-debug', group: :development
```

--------------------------------

### Define Custom Lookup Handler for I18n::Debug (Ruby)

Source: https://github.com/fphilipe/i18n-debug/blob/master/README.md

Sets a custom lambda or Proc to be executed every time an I18n lookup occurs. The handler receives the `key` and `value` of the lookup, enabling custom logic such as collecting statistics, sending data elsewhere, or modifying the logging format.

```Ruby
# Collect stats on I18n key usage.
i18n_stats = Hash.new { |stats, key| stats[key] = 0 }

I18n::Debug.on_lookup do |key, value|
  i18n_stats[key] += 1 if value
end
```

--------------------------------

### Set Custom Logger for I18n::Debug (Ruby)

Source: https://github.com/fphilipe/i18n-debug/blob/master/README.md

Assigns a custom logger object to `I18n::Debug.logger`. The custom logger must respond to the `debug` method, allowing users to integrate the gem's output with their preferred logging system.

```Ruby
I18n::Debug.logger = my_custom_logger
```

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