Add Tabs to Featured Page

With the frequency of overlapping spoiler seasons, we need a way to feature multiple different sets on the Featured tab at once. I am proposing a tab-based visual system, where users can switch tabs to view the different sets <img width="2129" height="1084" alt="Image" src="https://github.com/user-attachments/assets/c24630b9-f58c-43f6-93e7-641f8d22b37f" /> (An example of what I mean - obviously with masterful artistry) This idea was also supported by Don. I think the tab system above would look nice, and we would need at least 3 concurrent tabs to show here. Currently (as of writing this) we have three sets being spoiled: Edge of Eternities, Spider-Man, and Avatar. Having the ability to feature all of them at once would be very nice. The backend also needs to accommodate setting spoiler set codes for separate pages. Another probably quicker option is to simply have a drop-down menu to switch between the different featured sets at the time. This isn't as pretty from a UI standpoint but I'd imagine is quicker to execute in the short-term.