fix(iptv): keep remote focus inside the playlist dialog after typing

[ReichiMD]

Problem

Reported on Discord ("IPTV Unusable on Android TV") and r/ARVIO: on a Fire TV Stick the Add Playlist dialog closes on its own after typing M3U/Xtream details, so no playlist can be added. A second user: "after entering the details, the active button disappears". It works on an emulator with a mouse and on Google TV / Shield.

Cause

In IptvPlaylistModal, the D-pad exits of a text field call clearFocus() and then modalFocusRequester.requestFocus(). The keyboard's Done action and the Back key only call clearFocus(). Focus then goes to whatever Compose finds first. The full-screen scrim is clickable, so on a remote it is a focus target, and OK on it runs onDismiss. The highlight disappears (the dialog draws it from its own row state), and the next OK throws away everything typed. The full-screen Amazon keyboard on Fire TV is usually left with Done or Back, so Fire TV users hit this every time.
Also, hideKeyboardAll() called view.requestFocus() on a LocalView read outside Dialog {}, i.e. the activity's view behind the dialog.

Change (1 file, +48/-12)

• Done and Back in a field call a new onKeyboardClosed callback that returns focus to the dialog, the same way the D-pad exits already do (all eleven TV-layout fields; the touch layout passes nothing).
• hideKeyboardAll() focuses the dialog on TV instead of the activity view.
• The scrim and dismissOnClickOutside only dismiss on devices with a touchscreen (LocalHasTouchScreen). Phones and tablets keep tap-outside-to-close.

Testing

• Fire TV Stick 4K Max: 2.0.0 reproduces the bug. With this change the playlist can be added and the dialog stays usable with the remote, after leaving the keyboard with Done and with Back.
• Google TV (TCL C7K): unchanged (it never reproduced there).
• testSideloadDebugUnitTest: 1828 tests, 0 failures.
• Not covered by an automated test: the keyboard path goes through a native EditText inside an AndroidView, which the Compose test APIs cannot drive (pressImeActionButton only works on Compose text fields).

Not in this PR

• ModalScrim in SettingsScreen.kt (e.g. quality filter editor, cloud e-mail/password) and AppUpdateModal.kt use the same clickable scrim, so the same focus trap may exist there on TV. Left out to keep this PR small.
• Cancel/Save and the tabs are still focusable on TV. With focus now returned right away there is no known path to them, so they were left as they are.
• With a mouse on a TV without a touchscreen, clicking beside the dialog no longer closes it (Back and Cancel still do).

created by Claude (Anthropic) on behalf of @ReichiMD

[ProdigyV21]

Thanks for fixing this remote-focus path. I added a guard for late native keyboard callbacks and an on-device regression test. All 9 IPTV dialog tests passed on a TV emulator, including typing into the guide field, pressing Done, then navigating to Save with the D-pad. Play and Sideload Kotlin compilation also passed. Merging with your original commits preserved.