Custom Tabs: Ability to Pin/Unpin Tabs to the Tab Bar

[LePips]

Discussed in https://github.com/jellyfin/Swiftfin/discussions/1729

^{Originally posted by ascoolarobban September 23, 2025}
Hi!

I’d like to suggest two related features for Swiftfin:

1.	Dedicated “Documentaries” Tab
•	A separate tab in the app navigation specifically for documentaries.
•	Documentaries should be removed from the general Movies section to avoid duplication and keep browsing clean.

2.	Category Sorting for Movies
•	Add the ability to sort or filter movies by category (e.g., Action, Comedy, Drama, Sci-Fi).
•	Categories could map directly to existing metadata/genres in Jellyfin.

Use case:
These two features would make browsing large libraries much easier. For example, if I only want to watch a documentary, I could either go straight to the dedicated tab.

If this feature request is considered reasonable, I’d be happy to contribute with implementation.

[JPKribs]

Tagging #1752. I was starting to look at this one and it looks like that PR resolves (or at least starts) this!