Additional Voice Chat Features

[witabop]

Here's the run down of the general changes I did to make the voice chat experience feel a bit better!

Sound playback fix
Okay so this one wasn't actually related to voice chat but I needed to fix this for the join/leave call sounds below. Essentially all sound playback was bugged and not playing.

• Sounds were embedded as Resource and played via relative URIs when the WPF MediaPlayer needs real file paths.
• All .wav files under Resources/Sounds are now Content with CopyToOutputDirectory="PreserveNewest", and the new SoundHelper builds URIs from AppDomain.CurrentDomain.BaseDirectory so playback uses the copied files.
• Nudge/type/online and join/leave call sounds now use the same persistent chatSoundPlayer (or a static player in SoundHelper) so the player isn’t collected before MediaOpened fires.

Join/leave call sounds
It's pretty much what it says it is. Just adds a join and leave sound.

• OnVoiceStateUpdated compares Before.Channel?.Id and After.Channel?.Id to detect join/leave.

Speaking glow
does that green circle thing that happens when you talk on discord, though I changed it to fit the theme

• VoiceSocket maps SSRC to user (opcode 5) and computes RMS on incoming PCM; above a certain threshold sets “speaking” and a timer that clears it after ~300 ms.
• UserViewModel.IsSpeaking is updated from VoiceManager events; connected-user items use a DataTrigger on IsSpeaking to show a faint green gradient + DropShadowEffect.

Voice user context menu
Similar to how you can open a context menu when you right click someone in call on discord, you can do it here now.

• Profile: placeholder, my other MR implements the user profile popup so I couldn't attach it here yet.
• Mute: client = stop sending, others = stop playing their audio (per-SSRC mute in NAudioPlayer).
• Deafen: stop adding received audio to the mixer (SelfDeafened skips ProcessPacket).
• Volume Adjustment: I couldn't figure out how to do a slider so I did a submenu from 0%–200% (25% steps). Client = scale PCM before encode (ClientTransmitVolume); others = per-SSRC VolumeSampleProvider in the mixer.

[witabop]

holy fumble I forgot to git add the sound helper AND audio files