The type of environment that will be provisioned when launching the CLI for Commerce command magento-cloud environment:branch <environment-name> <parent-environment-id> is an integration environment with the code and database from the parent environment. Integration environments are temporary environments that are used for testing and development purposes on the Adobe Commerce Cloud platform. They can be created from any branch of code and have their own dedicated database and services. When creating an integration environment using the CLI for Commerce command, the code and database from the parent environment are copied to the new integration environment, creating an exact replica of the parent environment. Verified Reference: [Magento 2.4 DevDocs]

In Adobe Commerce, to retrieve custom extension attributes on an entity such as a quote, you need to ensure that these attributes are properly loaded when accessing the entity directly via repository interfaces. When fetching a single quote, it is essential to use a plugin on CartRepositoryInterface::get to include the extension attributes as this method is responsible for loading individual quote data.
If the plugin is missing for the get method, the extension attributes won't be loaded for single quote retrieval, leading to their absence in the result.
Additional Resources:
* Adobe Commerce Developer Guide: Extension Attributes
* Magento 2 Repositories and Plugins

The developer can achieve this by adding the following configuration to their di.xml file:
XML
<config>
<component name="Custom\Module\Model\Example" factory="Custom\Module\Model\ExampleFactory">
<arguments>
<argument name="filesystemAdapter" type="Magento\Filesystem\Adapter\Local" />
</arguments>
</component>
</config>
This configuration will ensure that all instances of the Custom\Module\Model\Example class will receive a new instance of the Magento\Filesystem\Adapter\Local class.

The command used to upgrade ECE-Tools on an Adobe Commerce Cloud platform is composer update magento/ece-tools --with-all-dependencies. This command will update the ECE-Tools package and its dependencies to the latest version available in the composer repository. The developer then needs to commit and push the changes to the composer.json and composer.lock files and redeploy the environment. Verified References: [Magento 2.4 DevDocs]

If the Sodium extension is installed, Argon 2ID13 will be chosen as the Magento default hashing algorithm.
Otherwise, SHA256 will be used.
The Sodium extension is a PHP extension that provides cryptographic functions. Argon 2ID13 is a password hashing algorithm that is considered to be more secure than SHA256.
If the Sodium extension is installed, Magento will use Argon 2ID13 as the default hashing algorithm for customer passwords. If the Sodium extension is not installed, Magento will use SHA256 as the default hashing algorithm.