fix: reuse loaded streams when Next Episode tapped during autoplay countdown

When the autoplay job has already located a stream for the next episode
and the countdown (3-2-1) is running, tapping the Next button cancels
the countdown coroutine and relaunches the full stream search from
scratch. This causes a visible 'Searching...' flicker and unnecessary
re-fetching of streams that were already found.

Fix: in playNextEpisode(), check episodeStreamsState for already-loaded
streams before starting a new search. If streams are present, cancel
the running job and immediately play the first one. Falls back to the
full search path only when no streams are yet available.

composeApp/src/commonMain/kotlin/com/nuvio/app/features/player/PlayerScreenRuntimeSourceActions.kt

@@ -371,6 +371,22 @@ internal fun PlayerScreenRuntime.switchToDownloadedEpisode(downloadItem: Downloa
 }
 
 internal fun PlayerScreenRuntime.playNextEpisode() {
+    // If streams for the next episode are already loaded (e.g. autoplay found one
+    // during its countdown), re-use them immediately instead of restarting the
+    // entire search. This prevents a visible "Searching…" flicker when the user
+    // manually taps the Next Episode button while the countdown is in progress.
+    val nextVideoId = nextEpisodeInfo?.videoId
+    val nextVideo = nextVideoId?.let { id -> playerMetaVideos.firstOrNull { it.id == id } }
+    if (nextVideo != null && nextEpisodeInfo?.hasAired == true) {
+        val cachedStreams = PlayerStreamsRepository.episodeStreamsState.value.groups
+            .flatMap { it.streams }
+        if (cachedStreams.isNotEmpty()) {
+            nextEpisodeAutoPlayJob?.cancel()
+            switchToEpisodeStream(cachedStreams.first(), nextVideo)
+            return
+        }
+    }
+
     scope.launchPlayerNextEpisodeAutoPlay(
         previousJob = nextEpisodeAutoPlayJob,
         nextEpisodeInfo = nextEpisodeInfo,