UI Responsiveness and Validation Fix

The interface no longer stutters periodically during your session -- a background security check was running on the main thread every 10 seconds and has been moved off it.

Fixes

• Fixed the error details panel showing no content when a validation error occurred -- it now displays the specific errors correctly
• Fixed a bug where the instance deletion dialog would get stuck after deleting an instance -- the confirmation input stayed visible and the dialog could not be closed