Add EventDef notices, morning and lesson bells, and info toasts.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/HSchool.Protocol/ProtocolCodec.cs

@@ -70,6 +70,14 @@ public static class ProtocolCodec
         return writer.Position;
     }
 
+    public static int WriteDismissNotice(Span<byte> destination, in ClientDismissNoticeMessage message)
+    {
+        var writer = new PacketWriter(destination);
+        writer.WriteMessageType(MessageType.ClientDismissNotice);
+        writer.WriteUInt32(message.Id);
+        return writer.Position;
+    }
+
     public static int WriteWelcome(Span<byte> destination, in ServerWelcomeMessage message)
     {
         var writer = new PacketWriter(destination);
@@ -271,6 +279,22 @@ public static class ProtocolCodec
         return writer.Position;
     }
 
+    public static int NoticeSize(in ServerNoticeMessage message) =>
+        sizeof(byte) + sizeof(uint) + StringSize(message.DefName) + sizeof(byte) + sizeof(byte) + sizeof(uint) + sizeof(uint);
+
+    public static int WriteNotice(Span<byte> destination, in ServerNoticeMessage message)
+    {
+        var writer = new PacketWriter(destination);
+        writer.WriteMessageType(MessageType.ServerNotice);
+        writer.WriteUInt32(message.Id);
+        writer.WriteString(message.DefName);
+        writer.WriteByte(message.Severity);
+        writer.WriteByte(message.Pause ? (byte)1 : (byte)0);
+        writer.WriteUInt32(message.TtlMs);
+        writer.WriteUInt32(message.PersonId);
+        return writer.Position;
+    }
+
     public static MessageType PeekMessageType(ReadOnlySpan<byte> source) =>
         source.IsEmpty ? MessageType.None : (MessageType)source[0];
 
@@ -441,6 +465,26 @@ public static class ProtocolCodec
         return new ServerPresenceMessage(schoolId, nodes, people);
     }
 
+    public static ClientDismissNoticeMessage ReadDismissNotice(ReadOnlySpan<byte> source)
+    {
+        var reader = new PacketReader(source);
+        Expect(ref reader, MessageType.ClientDismissNotice);
+        return new ClientDismissNoticeMessage(reader.ReadUInt32());
+    }
+
+    public static ServerNoticeMessage ReadNotice(ReadOnlySpan<byte> source)
+    {
+        var reader = new PacketReader(source);
+        Expect(ref reader, MessageType.ServerNotice);
+        var id = reader.ReadUInt32();
+        var defName = reader.ReadString();
+        var severity = reader.ReadByte();
+        var pause = reader.ReadByte() != 0;
+        var ttlMs = reader.ReadUInt32();
+        var personId = reader.ReadUInt32();
+        return new ServerNoticeMessage(id, defName, severity, pause, ttlMs, personId);
+    }
+
     private static bool HasPresenceActivity(PresenceNode node) =>
         node.ActivitySubject.Length > 0 || node.ActivityClass.Length > 0;