Change success logic in Options controller to treat the save as successful if any individual option update persisted (use OR instead of AND), preventing a single-failure from marking the whole operation as failed. Fix Options_model to return TRUE after inserting a new option so inserts are reported as successful. Add a saveFailed flash message display in the email options view so users see explicit failure alerts when appropriate.
Insert form_open('options/email_save') into the normal email configuration branch in application/views/options/email.php so the form is properly opened and will post to the email_save handler, enabling saving of email settings.
Fixes#3429
Added FontAwesome icons to options pages and sidebar for better visual distinction. Improved the options index page with overview cards for each settings category. Updated CSS for active and hover states in the options sidebar, providing a more modern and user-friendly interface. Added a subscription management link to the header if configured.
Introduces logic to detect and enforce centrally managed email settings. When managed, email options are displayed as read-only and cannot be changed by users; attempts to save changes are blocked with a notice. The email options view now conditionally renders a read-only summary and test email form if management is enabled.
Introduces email notifications when a logbook is shared with a new user, including a new email template and improved error logging for email sending. Also enhances the test email UI with a loading spinner and updates error messages for better clarity.
