feat: add session capacity waitlist

tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/NewSessionCommandParserTests.cs

@@ -13,6 +13,7 @@ public sealed class NewSessionCommandParserTests
             Название: Curse of Strahd
             Время: 24.04.2026 19:30
             Время: 01.05.2026 20:00
+            Мест: 4
             Ссылка: https://example.test/room
             """;
 
@@ -21,6 +22,7 @@ public sealed class NewSessionCommandParserTests
         Assert.True(result.IsValid);
         Assert.Equal("Curse of Strahd", result.Title);
         Assert.Equal("https://example.test/room", result.Link);
+        Assert.Equal(4, result.MaxPlayers);
         Assert.Equal(
             [
                 new DateTimeOffset(2026, 4, 24, 16, 30, 0, TimeSpan.Zero),
@@ -65,4 +67,22 @@ public sealed class NewSessionCommandParserTests
         Assert.False(result.IsValid);
         Assert.Null(result.Link);
     }
+
+    [Fact]
+    public void Parse_ShouldCollectInvalidSeatLimit()
+    {
+        var text = """
+            /newsession
+            Название: Blades in the Dark
+            Время: 25.04.2026 19:30
+            Мест: 0
+            Ссылка: https://example.test/blades
+            """;
+
+        var result = NewSessionCommandParser.Parse(text, DateTimeOffset.UtcNow);
+
+        Assert.False(result.IsValid);
+        Assert.Null(result.MaxPlayers);
+        Assert.Equal(["0"], result.InvalidSeatLimitInputs);
+    }
 }

tests/GmRelay.Bot.Tests/Features/Sessions/CreateSession/SessionCapacityRulesTests.cs

@@ -0,0 +1,31 @@
+using GmRelay.Bot.Features.Sessions.CreateSession;
+using GmRelay.Shared.Domain;
+
+namespace GmRelay.Bot.Tests.Features.Sessions.CreateSession;
+
+public sealed class SessionCapacityRulesTests
+{
+    [Fact]
+    public void DecideJoinStatus_ShouldReturnActive_WhenSessionHasFreeSeats()
+    {
+        var status = SessionCapacityRules.DecideJoinStatus(maxPlayers: 3, activeParticipants: 2);
+
+        Assert.Equal(ParticipantRegistrationStatus.Active, status);
+    }
+
+    [Fact]
+    public void DecideJoinStatus_ShouldReturnWaitlisted_WhenSessionReachedLimit()
+    {
+        var status = SessionCapacityRules.DecideJoinStatus(maxPlayers: 2, activeParticipants: 2);
+
+        Assert.Equal(ParticipantRegistrationStatus.Waitlisted, status);
+    }
+
+    [Fact]
+    public void CanPromoteWaitlistedPlayer_ShouldRequireWaitlistAndFreeSeat()
+    {
+        Assert.True(SessionCapacityRules.CanPromoteWaitlistedPlayer(maxPlayers: 3, activeParticipants: 2, waitlistedParticipants: 1));
+        Assert.False(SessionCapacityRules.CanPromoteWaitlistedPlayer(maxPlayers: 3, activeParticipants: 3, waitlistedParticipants: 1));
+        Assert.False(SessionCapacityRules.CanPromoteWaitlistedPlayer(maxPlayers: 3, activeParticipants: 2, waitlistedParticipants: 0));
+    }
+}