Use AAC audio codec for screen recordings (#3220)

AAC provides better cross-platform compatibility compared to Opus when
using MP4 containers. While Opus is supported in MP4, compatibility
varies across different media players and platforms.

In testing, screen recordings with Opus codec sent to Windows users
played without audio in Windows Media Player, while recordings with
AAC codec worked immediately without issues. AAC ensures recordings
are playable out-of-the-box across all platforms without requiring
users to install additional codecs or use alternative media players.

bin/omarchy-cmd-screenrecord

@@ -62,7 +62,7 @@ start_screenrecording() {
   # Merge audio tracks into one - separate tracks only play one at a time in most players
   [[ "$AUDIO" == "true" ]] && audio_args="-a default_output|default_input"
 
-  gpu-screen-recorder -w "$@" -f 60 -c mp4 -o "$filename" $audio_args &
+  gpu-screen-recorder -w "$@" -f 60 -c mp4 $audio_args -ac aac -o "$filename" &
   toggle_screenrecording_indicator
 }