Minor fixes

[gnattu]

This PR:

• Limits INMediaUserContext+Donate to fetch only one song. Previously, it was fetching all songs, which slowed down everything at boot.
• Improves buffering status checks. Now it considers buffering only when media is actually playing, preventing the now-playing bar from showing a loading spinner when the current playlist is finished. It also addresses a rare buffering case for completeness.
• Fixes the use of .infinity with .frame. It should be nil to set nothing, as .infinity is not a valid value for fixed size frames and defaults to nil anyway. Setting it to nil silences warnings.
• Fixes the Catalyst build by using the correct symbols.

Additionally, you need to change the build target to Mac Catalyst and run Archive to get a macOS-compatible app in .app. The previous builds only released an iOS app in .ipa.

I'm busy with bugfixing the server-side issue of 10.9 recently, if you have faced any server-side issue please ask and let me see what we can do on the server side.