fix(protocol): send disconnect packet when no servers available during login

[Copilot]

When a player connects but no backend servers are available, the proxy was closing the TCP connection without sending a disconnect packet. The client received no error message - just a dropped connection.

Root Cause

KickPlayerAsync returned false when the player wasn't in authenticated phases (Play/Configuration/post-LoginSuccess), preventing disconnect packet transmission. The conditional checks were:

// v1_20_2_to_latest example - similar in other versions
if (await player.IsPlayingAsync(cancellationToken))
    await channel.SendPacketAsync(new NbtDisconnectPacket { Reason = reason }, cancellationToken);
else if (await player.IsConfiguringAsync(cancellationToken))
    await channel.SendPacketAsync(new NbtDisconnectPacket { Reason = reason }, cancellationToken);
else if (await player.IsLoggingInAsync(cancellationToken))
    await channel.SendPacketAsync(new JsonDisconnectPacket { Reason = reason }, cancellationToken);
else
    return false;  // ← No packet sent

The IsLoggingInAsync check verified if LoginSuccessPacket was in the registry, which only occurs after successful login - not during early login failure scenarios.

Changes

• Simplified kick logic: Always attempt sending disconnect packet as fallback instead of returning false
• Removed redundant helpers: Deleted IsInLoginPhaseAsync methods (checked same registry as IsLoggingInAsync since both serverbound/clientbound Login mappings load simultaneously)
• Consistent implementation: Applied to all protocol versions (v1_7_2_to_1_12_2, v1_13_to_1_20_1, v1_20_2_to_latest)

// After fix
if (await player.IsPlayingAsync(cancellationToken))
    await channel.SendPacketAsync(new NbtDisconnectPacket { Reason = reason }, cancellationToken);
else if (await player.IsConfiguringAsync(cancellationToken))
    await channel.SendPacketAsync(new NbtDisconnectPacket { Reason = reason }, cancellationToken);
else
    // Fallback: send Login disconnect packet
    await channel.SendPacketAsync(new JsonDisconnectPacket { Reason = reason }, cancellationToken);

return true;

Players now receive "Failed to find a server for you" message before disconnection.

Original prompt

It does kick me without any message. No even a single packet arrived to the client. It just closes TCP connection, but I expect disconnect packet with message.

[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ForwardingSupport.Velocity.Services.ForwardingService event listener
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ForwardingSupport.Velocity.Services.ForwardingService event listener method OnPhaseChanged
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ForwardingSupport.Velocity.Services.ForwardingService event listener method OnMessageReceived
[19:38:31 VRB] [Void.Proxy.Plugins.Context.PluginAssemblyLoadContext] Loading System.Collections.Concurrent assembly into Void.Proxy.Plugins.ModsSupport.Forge.dll context
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ModsSupport.Forge.Services.HandshakeService event listener
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ModsSupport.Forge.Services.HandshakeService event listener method OnPlayerDisconnect
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ModsSupport.Forge.Services.HandshakeService event listener method OnServerboundHandshakeBuild
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ModsSupport.Forge.Services.HandshakeService event listener method OnLoginPluginMessageEvent
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ModsSupport.Forge.Services.HandshakeService event listener method OnMessageReceived
[19:38:31 VRB] [Void.Proxy.Events.EventService] Registering Void.Proxy.Plugins.ModsSupport.Forge.Services.HandshakeService event listener method OnPhaseChanged
[19:38:31 VRB] [Void.Proxy.Players.PlayerService] Player 10.42.4.0:42521 connecting
[19:38:31 VRB] [Void.Proxy.Links.LinkService] Looking for a server for 10.42.4.0:42521 player
[19:38:31 VRB] [Void.Proxy.Links.LinkService] Connecting 10.42.4.0:42521 player to a args-server-1 server
[19:38:31 VRB] [Void.Proxy.Plugins.Common.Network.Channels.Services.SimpleMinecraftChannelBuilderService] Searching for channel builder for a 10.42.4.0:42521 player
[19:38:31 VRB] [Void.Proxy.Events.EventService] Invoking SearchChannelBuilderEvent event
[19:38:31 VRB] [Void.Proxy.Plugins.Context.PluginAssemblyLoadContext] Loading System.Linq assembly into Void.Proxy.Plugins.ProtocolSupport.Java.v1_7_2_to_1_12_2.dll context
[19:38:31 VRB] [Void.Proxy.Plugins.Context.PluginAssemblyLoadContext] Loading System.Linq assembly into Void.Proxy.Plugins.ProtocolSupport.Java.v1_13_to_1_20_1.dll context
[19:38:31 VRB] [Void.Proxy.Plugins.Context.PluginAssemblyLoadContext] Loading System.Linq assembly into Void.Proxy.Plugins.ProtocolSupport.Java.v1_20_2_to_latest.dll context
[19:38:31 VRB] [Void.Proxy.Events.EventService] Completed invoking SearchChannelBuilderEvent event
[19:38:31 WRN] [Void.Proxy.Plugins.Common.Network.Channels.Services.SimpleMinecraftChannelBuilderService] Channel builder not found for a 10.42.4.0:42521 player
[19:38:31 VRB] [Void.Proxy.Plugins.Common.Network.Channels.Services.SimpleMinecraftChannelBuilderService] Building channel for a 10.42.4.0:42521 player
[19:38:31 VRB] [Void.Proxy.Plugins.Common.Network.Channels.Services.SimpleMinecraftChannelBuilderService] Client 10.42.4.0:42521 is using SimpleMinecraftChannel channel implementation
[19:38:31 VRB] [Void.Proxy.Events.EventService] Invoking ChannelCreatedEvent event
[19:38:31 VRB] [Void.Proxy.Events.EventService] Completed invoking ChannelCreatedEvent event
[19:38:31 VRB] [Void.Proxy.Plugins.Common.Network.Channels.Services.SimpleMinecraftChannelBuilderService] Building channel for a args-server-1 server
[19:38:31 WRN] [Void.Proxy.Links.LinkService] Player 10.42.4.0:42521 cannot connect to a args-server-1 server because it is unavailable: Name or service not known
[19:38:31 VRB] [Void.Proxy.Links.LinkService] Connecting 10.42.4.0:42521 player to a args-server-2 server
[19:38:31 VRB] [Void.Proxy.Plugins.Common.Network.Channels.Services.SimpleMinecraftChannelBuilderService] Building channel for a args-server-2 server
[19:38:31 WRN] [Void.Proxy.Links.LinkService] Player 10.42.4.0:42521 cannot connect to a args-server-2 server because it is unavailable: Name or service not known
[19:38:31 VRB] [Void.Proxy.Players.PlayerService] Kicking player 10.42.4.0:42521
[19:38:31 VRB] [Void.Proxy.Events.EventService] Invoking PlayerKickEvent event
[19:38:31 VRB] [Void.Proxy.Events.EventService] Completed invoking PlayerKickEvent event
[19:38:31 VRB] [Void.Proxy.Events.EventService] Invoking PlayerDisconnectedEvent event
[19:38:31 INF] [Void.Proxy.Players.PlayerService] Player 10.42.4.0:42521 disconnected
[19:38:31 VRB] [Void.Proxy.Events.EventService] Unregistering Void.Proxy.Plugins.ForwardingSupport.Velocity.Services.ForwardingService event listener
[19:38:31 VRB] [Void.Proxy.Events.EventService] Unregistering Void.Proxy...

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