Feature: Make archive/played more clear

### What problem does this address?

Currently, I have no idea what the difference is between marking an episode played or archived. Seems like they both serve the same purpose. Reading from the below docs, archive does everything most would need. Removing the episode from the list, removing the download, etc.

https://support.pocketcasts.com/article/archiving-episodes-2/

### What is your proposed solution?

Explain what marking as played does in docs, in the app, or maybe it is time to remove this feature in favor of archiving. This is all to avoid confusion.

### Did you search for existing feature suggestions?

- [X] I have searched for existing feature suggestions.

Start with the linked Pocket Casts support article, then compare the app's played and archived episode flows. The issue leaves open whether the fix belongs in documentation, the app, or feature removal, so a maintainer decision is needed first; done means the distinction and intended behavior are clearly documented and no longer confusing.

Written by the indexing model from the issue text.