Regression Testing 5.1

Fixed: Issue where the "Scan" button remained enabled when the website had a connection error.
Fixed: Page reload issue that occurred after closing the scan modal window.
Fixed: Incorrect error message displayed when the dashboard plugin is disabled.
Added: Condition check before executing the cron job for sending email notifications to prevent unnecessary processing.
Added: Function to automatically delete website data when a site is removed from MainWP to maintain database cleanliness.
Added: Option to set custom retention time for HTML snapshots, allowing users to control storage duration.
Added: HTTP authentication login support for sites requiring basic authentication credentials.
Updated: Automatic update logic to check only the homepage when users enable automatic updates, improving scan efficiency
Updated: Manual scan process to use batched cron jobs that scan 3 pages at a time instead of scanning all pages simultaneously, reducing server load.
Updated: Scanning logic to exclude and remove pages that cannot be connected to, preventing failed scan attempts.
Updated: Modal close button styling with improved color scheme and repositioned buttons for better accessibility.
Updated: Replaced instances of the 'mainwp' text domain with 'mainwp-regression-testing-extension' for improved localization consistency.