Remove legacy mode.

- Deleted the legacy WebSocket client implementation (`wstoclient.go`) and its test file (`wstoclient_test.go`).
- Removed legacy handling from the HTTP manager, including legacy proxy setup and routing.
- Cleaned up session management by removing legacy host checks and related functions.
- Eliminated the legacy WebRTC handler and its associated logic.
- Updated session interface to remove legacy methods.
- Removed legacy API documentation and configuration options from migration guide and help files.

server/internal/session/session.go

@@ -47,16 +47,11 @@ func (session *SessionCtx) profileChanged() {
 	}
 
 	if (!session.profile.CanConnect || !session.profile.CanLogin || !session.profile.CanWatch) && session.state.IsWatching {
-		// TODO: Needed for legacy implementation. Websocket must die before webrtc and deliver signal close message
-		// otherwise webrtc destroy would trigger websocket reconnect. In case of kick event, webrtc destroy is called
-		// before websocket destroy that delivers the information about the kick.
-		time.AfterFunc(time.Second, func() {
-			// The peer may have been removed if the user disconnected while
-			// waiting for the delayed teardown.
-			if webrtcPeer := session.GetWebRTCPeer(); webrtcPeer != nil {
-				webrtcPeer.Destroy()
-			}
-		})
+		// The peer may have been removed if the user disconnected while
+		// waiting for the delayed teardown.
+		if webrtcPeer := session.GetWebRTCPeer(); webrtcPeer != nil {
+			webrtcPeer.Destroy()
+		}
 	}
 
 	if (!session.profile.CanConnect || !session.profile.CanLogin) && session.state.IsConnected {
@@ -77,18 +72,6 @@ func (session *SessionCtx) IsHost() bool {
 	return session.manager.isHost(session)
 }
 
-// only needed for legacy webrtc handler
-func (session *SessionCtx) LegacyIsHost() bool {
-	settings := session.manager.Settings()
-	if !session.profile.CanHost || session.PrivateModeEnabled() {
-		return false
-	}
-	if settings.LockedControls && !session.profile.IsAdmin {
-		return false
-	}
-	return settings.ImplicitHosting || session.manager.isHost(session)
-}
-
 func (session *SessionCtx) SetAsHost() {
 	session.manager.setHost(session, session)
 }