feat: add world chat UI

Server/Framework.Shared.Tests/FrameworkMessagesTests.cs

@@ -86,6 +86,27 @@ namespace XWorld.Framework.Tests
             Assert.Equal("version mismatch", d.Message);
         }
 
+        [Fact]
+        public void WorldChatMessages_RoundTrip()
+        {
+            var send = new WorldChatSendMsg { Text = "hello world" };
+            WorldChatSendMsg decodedSend = WorldChatSendMsg.Decode(send.Encode());
+            Assert.Equal("hello world", decodedSend.Text);
+
+            var broadcast = new WorldChatMessageMsg
+            {
+                PlayerId = 42,
+                PlayerName = "Alice",
+                Text = "hello everyone",
+                ServerTimeMs = 123456789L
+            };
+            WorldChatMessageMsg decodedBroadcast = WorldChatMessageMsg.Decode(broadcast.Encode());
+            Assert.Equal(42, decodedBroadcast.PlayerId);
+            Assert.Equal("Alice", decodedBroadcast.PlayerName);
+            Assert.Equal("hello everyone", decodedBroadcast.Text);
+            Assert.Equal(123456789L, decodedBroadcast.ServerTimeMs);
+        }
+
         [Fact]
         public void Opcodes_AreStableValues()
         {
@@ -97,6 +118,8 @@ namespace XWorld.Framework.Tests
             Assert.Equal((ushort)5, (ushort)FrameworkOpcode.Snapshot);
             Assert.Equal((ushort)6, (ushort)FrameworkOpcode.RoomEnd);
             Assert.Equal((ushort)7, (ushort)FrameworkOpcode.Error);
+            Assert.Equal((ushort)16, (ushort)FrameworkOpcode.WorldChatSend);
+            Assert.Equal((ushort)17, (ushort)FrameworkOpcode.WorldChatMessage);
         }
 
         [Fact]

Server/Gateway.Tests/ServerLoopTests.cs

@@ -32,6 +32,10 @@ namespace XWorld.Server.Gateway.Tests
                     Moving = moving
                 }.Encode());
 
+        private static Frame WorldChatFrame(string text)
+            => new Frame(Channel.Framework, (ushort)FrameworkOpcode.WorldChatSend,
+                new WorldChatSendMsg { Text = text }.Encode());
+
         private static List<Frame> Frames(FakeConnection c)
         {
             var list = new List<Frame>();
@@ -85,6 +89,35 @@ namespace XWorld.Server.Gateway.Tests
             Assert.True(decoded.Moving);
         }
 
+        [Fact]
+        public void WorldChat_IsBroadcastToAllConnectedPlayers()
+        {
+            var loop = NewLoop();
+            var c1 = new FakeConnection(1);
+            var c2 = new FakeConnection(2);
+            loop.Submit(new ConnectCommand { PlayerId = 1, Connection = c1 });
+            loop.Submit(new ConnectCommand { PlayerId = 2, Connection = c2 });
+            loop.Submit(new FrameCommand { PlayerId = 1, Frame = LobbyJoinFrame("Alice") });
+            loop.Submit(new FrameCommand { PlayerId = 2, Frame = LobbyJoinFrame("Bob") });
+            loop.DrainAndTick(0f);
+
+            c1.Sent.Clear();
+            c2.Sent.Clear();
+            loop.Submit(new FrameCommand { PlayerId = 1, Frame = WorldChatFrame("hello world") });
+            loop.DrainAndTick(0f);
+
+            Frame selfFrame = Frames(c1).Find(f => f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.WorldChatMessage);
+            Frame otherFrame = Frames(c2).Find(f => f.Channel == Channel.Framework && f.Opcode == (ushort)FrameworkOpcode.WorldChatMessage);
+            Assert.NotEqual(default, selfFrame);
+            Assert.NotEqual(default, otherFrame);
+
+            WorldChatMessageMsg message = WorldChatMessageMsg.Decode(otherFrame.Payload);
+            Assert.Equal(1, message.PlayerId);
+            Assert.Equal("Alice", message.PlayerName);
+            Assert.Equal("hello world", message.Text);
+            Assert.True(message.ServerTimeMs > 0);
+        }
+
         [Fact]
         public void Reconnect_ReroutesRoomOutputToNewConnection()
         {

Server/Gateway/ServerLoop.cs

@@ -21,6 +21,7 @@ namespace XWorld.Server.Gateway
         private readonly Matchmaker _matchmaker;
         private readonly ChannelsNS.Channel<ServerCommand> _cmds =
             ChannelsNS.Channel.CreateUnbounded<ServerCommand>();
+        private const int MaxWorldChatTextLength = 200;
         private readonly Dictionary<string, List<int>> _roomPlayers = new Dictionary<string, List<int>>();
         private readonly Dictionary<int, LobbyPlayerMsg> _lobbyPlayers = new Dictionary<int, LobbyPlayerMsg>();
         private readonly Dictionary<string, int> _playerCountCache = new Dictionary<string, int>(); // "gameId@version" -> playerCount
@@ -156,6 +157,9 @@ namespace XWorld.Server.Gateway
                 case FrameworkOpcode.LobbyLeave:
                     if (_lobbyPlayers.Remove(pid)) BroadcastLobbyState();
                     break;
+                case FrameworkOpcode.WorldChatSend:
+                    HandleWorldChatSend(pid, frame.Payload);
+                    break;
             }
         }
 
@@ -213,6 +217,41 @@ namespace XWorld.Server.Gateway
             }
         }
 
+        private void HandleWorldChatSend(int pid, byte[] payload)
+        {
+            if (!_sessions.IsConnected(pid))
+            {
+                return;
+            }
+
+            var req = WorldChatSendMsg.Decode(payload);
+            string text = (req.Text ?? string.Empty).Trim();
+            if (text.Length == 0)
+            {
+                return;
+            }
+            if (text.Length > MaxWorldChatTextLength)
+            {
+                text = text.Substring(0, MaxWorldChatTextLength);
+            }
+
+            string name = _lobbyPlayers.TryGetValue(pid, out var player) && !string.IsNullOrWhiteSpace(player.Name)
+                ? player.Name
+                : $"P{pid}";
+            var msg = new WorldChatMessageMsg
+            {
+                PlayerId = pid,
+                PlayerName = name,
+                Text = text,
+                ServerTimeMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()
+            };
+            byte[] encoded = msg.Encode();
+            foreach (int targetPid in _sessions.ConnectedPlayerIds())
+            {
+                SendFramework(targetPid, FrameworkOpcode.WorldChatMessage, encoded);
+            }
+        }
+
         private void BroadcastLobbyState()
         {
             if (_lobbyPlayers.Count == 0) return;

Server/Gateway/SessionManager.cs

@@ -38,6 +38,19 @@ namespace XWorld.Server.Gateway
 
         public Session Get(int pid) => _byPid.TryGetValue(pid, out var s) ? s : null;
 
+        public IReadOnlyList<int> ConnectedPlayerIds()
+        {
+            List<int> players = null;
+            foreach (var kv in _byPid)
+            {
+                if (kv.Value.Connected)
+                {
+                    (players ??= new List<int>()).Add(kv.Key);
+                }
+            }
+            return players ?? (IReadOnlyList<int>)Array.Empty<int>();
+        }
+
         /// <summary>移除断线且"严格越过"重连窗口的会话（currentTick - DisconnectedAtTick &gt; windowTicks）。返回被移除的会话；无则空数组。</summary>
         public IReadOnlyList<Session> SweepExpired(long currentTick, long windowTicks)
         {