fix: server-deafen now shows amber mute icon across all UI surfaces

When a moderator server-deafens a user, the implied mute is server-imposed
and should display amber (not red) everywhere. Updated VoiceControlBar,
ChannelSidebar, VoiceChannel, and VoiceUser to check isServerDeafened
alongside isServerMuted for amber color and cursor-not-allowed state.

Also includes smart mute/deafen toggle logic (Discord-style coupling),
server-side enforcement of mute/deafen bypass, and cleanup of server
voice state on user departure.

packages/web/src/components/voice/VoiceChannel.tsx

@@ -111,8 +111,8 @@ export function VoiceChannel({ channelId, channelName, onClick, locked }: VoiceC
                 <span className="text-[13px] text-txt-secondary truncate flex-1 min-w-0">{displayName}</span>
                 {/* Status badges */}
                 <div className="flex items-center gap-1 flex-shrink-0">
-                  {isServerMuted && (
-                    <span title="Server Muted">
+                  {(isServerMuted || isServerDeafened) && (
+                    <span title={isServerMuted ? "Server Muted" : "Muted (Server Deafened)"}>
                       <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor" className="text-accent-amber">
                         <path d="M12 14c1.66 0 3-1.34 3-3V5c0-1.66-1.34-3-3-3S9 3.34 9 5v6c0 1.66 1.34 3 3 3z" />
                         <path d="M17 11c0 2.76-2.24 5-5 5s-5-2.24-5-5H5c0 3.53 2.61 6.43 6 6.92V21h2v-3.08c3.39-.49 6-3.39 6-6.92h-2z" />
@@ -128,7 +128,7 @@ export function VoiceChannel({ channelId, channelName, onClick, locked }: VoiceC
                       </svg>
                     </span>
                   )}
-                  {!isServerMuted && isMuted && (
+                  {!isServerMuted && !isServerDeafened && isMuted && (
                     <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor" className="text-txt-danger">
                       <path d="M12 14c1.66 0 3-1.34 3-3V5c0-1.66-1.34-3-3-3S9 3.34 9 5v6c0 1.66 1.34 3 3 3z" />
                       <path d="M17 11c0 2.76-2.24 5-5 5s-5-2.24-5-5H5c0 3.53 2.61 6.43 6 6.92V21h2v-3.08c3.39-.49 6-3.39 6-6.92h-2z" />