fix(bot): skip join-link reminders without links

Prevent offline sessions with empty join links from entering the 5-minute join-link notification flow, omit blank link lines from direct reminders, and add offline persistence/reminder regression coverage.

tests/GmRelay.Bot.Tests/Infrastructure/Scheduling/DbSessionTriggerStoreTests.cs

@@ -0,0 +1,68 @@
+using GmRelay.Bot.Tests.Features.Sessions.CreateSession;
+using GmRelay.Shared.Domain;
+using GmRelay.Shared.Infrastructure.Scheduling;
+using GmRelay.Shared.Platform;
+using Npgsql;
+
+namespace GmRelay.Bot.Tests.Infrastructure.Scheduling;
+
+[Collection(CreateSessionHandlerPostgresCollection.Name)]
+public sealed class DbSessionTriggerStoreTests(CreateSessionHandlerPostgresFixture fixture)
+{
+    [Fact]
+    public async Task GetSessionsNeedingJoinLinkAsync_IgnoresConfirmedSessionsWithoutJoinLink()
+    {
+        var connectionString = await fixture.CreateMigratedDatabaseAsync();
+        await using var dataSource = NpgsqlDataSource.Create(connectionString);
+        await using var connection = await dataSource.OpenConnectionAsync();
+
+        var groupId = await InsertTelegramGroupAsync(connection);
+        var dueAt = DateTimeOffset.UtcNow.AddMinutes(4).UtcDateTime;
+        var onlineSessionId = await InsertSessionAsync(connection, groupId, dueAt, "https://vtt.example/game", "Online");
+        var offlineSessionId = await InsertSessionAsync(connection, groupId, dueAt, string.Empty, "Offline");
+
+        var sut = new DbSessionTriggerStore(dataSource, new PlatformSchedulerOptions(PlatformKind.Telegram));
+
+        var result = await sut.GetSessionsNeedingJoinLinkAsync(DateTimeOffset.UtcNow, CancellationToken.None);
+
+        Assert.Contains(onlineSessionId, result);
+        Assert.DoesNotContain(offlineSessionId, result);
+    }
+
+    private static async Task<Guid> InsertTelegramGroupAsync(NpgsqlConnection connection)
+    {
+        await using var command = new NpgsqlCommand(
+            """
+            INSERT INTO game_groups (name, platform, external_group_id)
+            VALUES ('Trigger Test Group', 'Telegram', @ExternalGroupId)
+            RETURNING id
+            """,
+            connection);
+        command.Parameters.AddWithValue("ExternalGroupId", Guid.NewGuid().ToString("N"));
+
+        return (Guid)(await command.ExecuteScalarAsync() ?? throw new InvalidOperationException("Group insert failed."));
+    }
+
+    private static async Task<Guid> InsertSessionAsync(
+        NpgsqlConnection connection,
+        Guid groupId,
+        DateTime scheduledAt,
+        string joinLink,
+        string format)
+    {
+        await using var command = new NpgsqlCommand(
+            """
+            INSERT INTO sessions (group_id, title, join_link, scheduled_at, status, format)
+            VALUES (@GroupId, 'Trigger Test Session', @JoinLink, @ScheduledAt, @Status, @Format)
+            RETURNING id
+            """,
+            connection);
+        command.Parameters.AddWithValue("GroupId", groupId);
+        command.Parameters.AddWithValue("JoinLink", joinLink);
+        command.Parameters.AddWithValue("ScheduledAt", scheduledAt);
+        command.Parameters.AddWithValue("Status", SessionStatus.Confirmed);
+        command.Parameters.AddWithValue("Format", format);
+
+        return (Guid)(await command.ExecuteScalarAsync() ?? throw new InvalidOperationException("Session insert failed."));
+    }
+}

tests/GmRelay.Bot.Tests/Infrastructure/Telegram/TelegramPlatformMessengerTests.cs

@@ -2,6 +2,7 @@ using GmRelay.Bot.Infrastructure.Telegram;
 using GmRelay.Shared.Platform;
 using GmRelay.Shared.Rendering;
 using Microsoft.Extensions.Logging.Abstractions;
+using System.Reflection;
 
 namespace GmRelay.Bot.Tests.Infrastructure.Telegram;
 
@@ -36,9 +37,35 @@ public sealed class TelegramPlatformMessengerTests
         Assert.Contains("Existing schedule message reference must match the schedule group.", exception.Message);
     }
 
+    [Fact]
+    public void BuildDirectNotificationText_OneHourReminderWithoutJoinLink_ShouldNotRenderBlankLinkLine()
+    {
+        var notification = new PlatformDirectSessionNotification(
+            PlatformDirectSessionNotificationKind.OneHourReminder,
+            new PlatformUser(PlatformKind.Telegram, "123", "Player", "player"),
+            Guid.NewGuid(),
+            "Offline Game",
+            DateTime.UtcNow,
+            JoinLink: string.Empty);
+
+        var text = InvokeBuildDirectNotificationText(notification);
+
+        Assert.DoesNotContain("🔗", text);
+    }
+
     private static TelegramPlatformMessenger CreateMessenger() =>
         new(null!, NullLogger<TelegramPlatformMessenger>.Instance);
 
+    private static string InvokeBuildDirectNotificationText(PlatformDirectSessionNotification notification)
+    {
+        var method = typeof(TelegramPlatformMessenger).GetMethod(
+            "BuildDirectNotificationText",
+            BindingFlags.NonPublic | BindingFlags.Static);
+
+        Assert.NotNull(method);
+        return Assert.IsType<string>(method.Invoke(null, new object[] { notification }));
+    }
+
     private static SessionBatchViewModel CreateView() =>
         new("Test batch", []);
 }