Inconsistent Duplicate Page Folder Name Handling

[thekenshow]

I ran into this in the Admin with a custom page type created via the Add menu. I don't want the user to see or choose a folder name, it should be generated from the title. But if there's an existing folder that matches the autogenerated title folder, I don't want the user having to figure out which folders have been created and which haven't. The solution is to detect an existing folder and append a "-2" (for example) so the page addition creation never fails.

Problem

The flex-objects controller has dedup logic for taskCopy() (via findFirstAvailable()), but the continuePages() method that handles "create new page" just throws an error on duplicates. It's an inconsistency — copy handles it gracefully, create doesn't.

Solution

Adding the same findFirstAvailable() logic to continuePages(). It's a small change that benefits anyone using add_modals with auto-generated slugs.