Add universal search screen with classic search toggle

[obiwantoby]

Changes

• Universal Search Screen: New dedicated search screen that queries the Jellyfin API with debounced requests (300ms) across Audio, Albums, Artists, Playlists, and Genres
• Rich Search Results: Uses TrackListTile for audio items and ItemCollectionWrapper for albums/artists/playlists to maintain consistency with existing app UI
• Classic Search Toggle: Added useUniversalSearch setting (HiveField 144) with a toggle in Layout & Theme settings. Users can switch back to the in-page classic search if preferred
• Search Integration: Search icon in the app bar and drawer menu entry now route to universal or classic search based on the user's preference setting
• iOS 26 Crash Fix: Added FLTEnableTouchRateCorrection=false to Debug, Release, and Profile plists to resolve VSyncClient crash on iOS 26 devices
• iOS file_picker Fix: Added Podfile preprocessor rename for FileUtils → FPFileUtils to resolve class collision with OSAnalytics framework
• Dependency Bump: Updated file_picker to ^10.3.10 for compatibility fixes

Todo before merging

• Translations (English strings added to app_en.arb; other language translations will follow)
• Reset Settings (useUniversalSearch reset support added to resetLayoutSettings)
• Extended CONTRIBUTING.md

Related Issues

• closes Allow searching for songs using artist's name. #471

Note this did fix an inappropriate pull request to which some other dart code was removed.

[Chaphasilor]

Thanks for the (new) PR!
I haven't tried it out yet, but looking at the code this doesn't support offline mode yet. Could you look into adding this?

Some more things you might want to consider:

1. Originally it was planned to add global search along with the new home screen (✨ Home Screen #1141), but I didn't have time to add both. You could consider updating the target branch to that PR branch, the branches should be mostly compatible (just the Hive IDs might change, and then you will need to run code generation again)
2. Splitting your changes into separate commits would be nice, but you can do that next time. Try to separate different changes as much as possible.
3. There is an existing more or less complete mockup for the global search:

This is just a **rough** mockup, and somewhat outdated. Don't mind how the item tiles look, don't mind the dark mode, don't mind the colors. The important bit would be the tabs / item types to search in, which can be toggled on and off. It would also be good if were obvious which kind of item is being shown.

4. This will now keep the old and new search implementation around, which isn't ideal. I don't see a reason to keep the old search function around, aside from filtering maybe?

[Chaphasilor]

@obiwantoby are you planning to make any further changes here? If not, I'll have to close the PR :)