Add in-app & Android TV screensaver (#946)

## Description
Adds both an optional in-app and Android TV OS (DreamService)
screensaver

Has settings for:
- Starting delay, options from 30s to 1 hour
- Duration to show each image, 30s to 2 minutes
- Show clock (separate from app-wide clock)
- Toggle animated zooming
- Set a max age rating to limit what content is shown
- Included media types: movies, tv shows, and/or photos

By default only Movies & TV Shows are included. But if you have like
family albums on your server, you could enable Photos too.

There's also an button to start the screensaver so you can see what it
looks like.

### Related issues
Closes #230

### Testing
Emulator, Onn 4k pro, nvidia shield using both in-app and OS
screensavers

## Screenshots
![screensaver_settings
Large](https://github.com/user-attachments/assets/9b3240dd-81cb-4c20-bc4e-b2bf38698b2f)

## AI or LLM usage
None

## Acknowledgements

Some of the skeleton code for setting up the `DreamService` with the
right lifecycle was copied and modified from the [official app's
implementation](https://github.com/jellyfin/jellyfin-androidtv/blob/master/app/src/main/java/org/jellyfin/androidtv/integration/dream/DreamServiceCompat.kt).

app/src/main/java/com/github/damontecres/wholphin/MainActivity.kt

@@ -3,10 +3,12 @@ package com.github.damontecres.wholphin
 import android.content.Intent
 import android.content.res.Configuration
 import android.os.Bundle
+import android.view.KeyEvent
 import android.view.WindowManager
 import androidx.activity.compose.setContent
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
+import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
@@ -49,6 +51,7 @@ import com.github.damontecres.wholphin.services.ImageUrlService
 import com.github.damontecres.wholphin.services.NavigationManager
 import com.github.damontecres.wholphin.services.PlaybackLifecycleObserver
 import com.github.damontecres.wholphin.services.RefreshRateService
+import com.github.damontecres.wholphin.services.ScreensaverService
 import com.github.damontecres.wholphin.services.ServerEventListener
 import com.github.damontecres.wholphin.services.SetupDestination
 import com.github.damontecres.wholphin.services.SetupNavigationManager
@@ -59,8 +62,10 @@ import com.github.damontecres.wholphin.services.hilt.AuthOkHttpClient
 import com.github.damontecres.wholphin.services.tvprovider.TvProviderSchedulerService
 import com.github.damontecres.wholphin.ui.CoilConfig
 import com.github.damontecres.wholphin.ui.LocalImageUrlService
+import com.github.damontecres.wholphin.ui.components.AppScreensaver
 import com.github.damontecres.wholphin.ui.components.LoadingPage
 import com.github.damontecres.wholphin.ui.detail.series.SeasonEpisodeIds
+import com.github.damontecres.wholphin.ui.launchDefault
 import com.github.damontecres.wholphin.ui.launchIO
 import com.github.damontecres.wholphin.ui.nav.ApplicationContent
 import com.github.damontecres.wholphin.ui.nav.Destination
@@ -134,6 +139,9 @@ class MainActivity : AppCompatActivity() {
     @Inject
     lateinit var datePlayedInvalidationService: DatePlayedInvalidationService
 
+    @Inject
+    lateinit var screensaverService: ScreensaverService
+
     private var signInAuto = true
 
     @OptIn(ExperimentalTvMaterial3Api::class)
@@ -317,6 +325,15 @@ class MainActivity : AppCompatActivity() {
                                     }
                                 },
                             )
+                            val screenSaverState by screensaverService.state.collectAsState()
+                            if (screenSaverState.enabled || screenSaverState.enabledTemp) {
+                                AnimatedVisibility(
+                                    screenSaverState.show,
+                                    Modifier.fillMaxSize(),
+                                ) {
+                                    AppScreensaver(appPreferences, Modifier.fillMaxSize())
+                                }
+                            }
                         }
                     }
                 }
@@ -324,10 +341,22 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    override fun dispatchKeyEvent(event: KeyEvent): Boolean {
+        if (screensaverService.state.value.show) {
+            screensaverService.stop(false)
+            screensaverService.pulse()
+            return true
+        } else {
+            screensaverService.pulse()
+            return super.dispatchKeyEvent(event)
+        }
+    }
+
     override fun onResume() {
         super.onResume()
         Timber.d("onResume")
-        lifecycleScope.launchIO {
+        lifecycleScope.launchDefault {
+            screensaverService.pulse()
             appUpgradeHandler.run()
         }
     }
@@ -341,6 +370,7 @@ class MainActivity : AppCompatActivity() {
     override fun onStop() {
         super.onStop()
         Timber.d("onStop")
+        screensaverService.stop(true)
         tvProviderSchedulerService.launchOneTimeRefresh()
     }