fix(media): video respects max height, stays within NoteCard bounds

Remove fillMaxWidth before aspectRatio so the caller's heightIn(max)
constraint is respected. Video now sizes to fit within the NoteCard
without overlapping the author header or overflowing the card.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/media/DesktopVideoPlayer.kt

@@ -251,7 +251,6 @@ fun DesktopVideoPlayer(
     Box(
         modifier =
             modifier
-                .fillMaxWidth()
                 .aspectRatio(aspectRatio)
                 .background(
                     MaterialTheme.colorScheme.surfaceContainerHigh,