feat: implement Blazor web interface for GM session management

- Created GmRelay.Web project (Blazor Server)
- Created GmRelay.Shared library for domain models and rendering
- Refactored GmRelay.Bot to use the Shared library
- Integrated Telegram Login widget with server-side HMAC verification
- Added Dashboard, Group Details, and Edit Session pages
- Enabled bot notifications and in-place message updates from web actions
- Updated .NET Aspire orchestration and Docker Compose configuration

src/GmRelay.Shared/Domain/MoscowTime.cs

@@ -0,0 +1,34 @@
+namespace GmRelay.Shared.Domain;
+
+public static class MoscowTime
+{
+    private static readonly TimeSpan MoscowOffset = TimeSpan.FromHours(3);
+
+    public static DateTimeOffset Now => DateTimeOffset.UtcNow.ToOffset(MoscowOffset);
+
+    public static DateTimeOffset ToMoscow(this DateTimeOffset utc) => utc.ToOffset(MoscowOffset);
+
+    public static string FormatMoscow(this DateTimeOffset utc)
+        => utc.ToOffset(MoscowOffset).ToString("d MMMM yyyy, HH:mm", System.Globalization.CultureInfo.GetCultureInfo("ru-RU"));
+
+    public static DateTime ToMoscow(this DateTime utcDt) => utcDt.Add(MoscowOffset);
+
+    public static string FormatMoscow(this DateTime utcDt)
+        => utcDt.Add(MoscowOffset).ToString("d MMMM yyyy, HH:mm", System.Globalization.CultureInfo.GetCultureInfo("ru-RU"));
+
+    public static string FormatMoscowShort(this DateTime utcDt)
+        => utcDt.Add(MoscowOffset).ToString("dd.MM");
+
+    public static bool TryParseMoscow(string text, out DateTimeOffset utcTime)
+    {
+        if (DateTime.TryParseExact(text, new[] { "dd.MM.yyyy HH:mm", "dd.MM.yyyy H:mm", "d.MM.yyyy HH:mm" }, 
+            System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out var localDt))
+        {
+            utcTime = new DateTimeOffset(localDt, MoscowOffset).ToUniversalTime();
+            return true;
+        }
+
+        utcTime = default;
+        return false;
+    }
+}

src/GmRelay.Shared/Domain/RsvpStatus.cs

@@ -0,0 +1,8 @@
+namespace GmRelay.Shared.Domain;
+
+public static class RsvpStatus
+{
+    public const string Pending = "Pending";
+    public const string Confirmed = "Confirmed";
+    public const string Declined = "Declined";
+}

src/GmRelay.Shared/Domain/SessionStatus.cs

@@ -0,0 +1,9 @@
+namespace GmRelay.Shared.Domain;
+
+public static class SessionStatus
+{
+    public const string Planned = "Planned";
+    public const string ConfirmationSent = "ConfirmationSent";
+    public const string Confirmed = "Confirmed";
+    public const string Cancelled = "Cancelled";
+}

src/GmRelay.Shared/GmRelay.Shared.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <LangVersion>preview</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Telegram.Bot" Version="22.9.5.3" />
+  </ItemGroup>
+
+</Project>

src/GmRelay.Shared/Rendering/SessionBatchRenderer.cs

@@ -0,0 +1,62 @@
+using GmRelay.Shared.Domain;
+using Telegram.Bot.Types.ReplyMarkups;
+
+namespace GmRelay.Shared.Rendering;
+
+public sealed record SessionBatchDto(Guid SessionId, DateTime ScheduledAt, string Status);
+public sealed record ParticipantBatchDto(Guid SessionId, string DisplayName, string? TelegramUsername);
+
+public static class SessionBatchRenderer
+{
+    public static (string Text, InlineKeyboardMarkup Markup) Render(
+        string title,
+        IReadOnlyList<SessionBatchDto> sessions,
+        IReadOnlyList<ParticipantBatchDto> participants)
+    {
+        var activeSessions = sessions.OrderBy(s => s.ScheduledAt).ToList();
+        
+        var messageText = $"🎲 <b>Новые игры:</b> {System.Net.WebUtility.HtmlEncode(title)}\n\n" +
+                          $"<b>Расписание:</b>\n\n";
+
+        var buttons = new List<InlineKeyboardButton[]>();
+
+        foreach (var session in activeSessions)
+        {
+            var sessionPlayers = participants.Where(p => p.SessionId == session.SessionId).ToList();
+            
+            messageText += $"📅 <b>{session.ScheduledAt.FormatMoscow()}</b>\n";
+            messageText += $"👥 Игроки ({sessionPlayers.Count}):\n";
+            
+            if (sessionPlayers.Count > 0)
+            {
+                messageText += string.Join("\n", sessionPlayers.Select(p => $"  👤 {(p.TelegramUsername != null ? "@" + p.TelegramUsername : p.DisplayName)}")) + "\n";
+            }
+            else
+            {
+                messageText += "  <i>Пока никто не записался</i>\n";
+            }
+
+            if (session.Status == "Cancelled")
+            {
+                messageText += "❌ <i>Сессия отменена</i>\n\n";
+            }
+            else if (session.Status == "RecruitmentClosed") 
+            {
+                messageText += "🔒 <i>Набор завершен</i>\n\n";
+            }
+            else
+            {
+                messageText += "\n";
+                var dateTitle = session.ScheduledAt.FormatMoscowShort();
+                buttons.Add(new[]
+                {
+                    InlineKeyboardButton.WithCallbackData($"✋ На {dateTitle}", $"join_session:{session.SessionId}"),
+                    InlineKeyboardButton.WithCallbackData($"❌ Отменить {dateTitle} (ГМ)", $"cancel_session:{session.SessionId}"),
+                    InlineKeyboardButton.WithCallbackData($"⏰ (ГМ)", $"reschedule_session:{session.SessionId}")
+                });
+            }
+        }
+
+        return (messageText, new InlineKeyboardMarkup(buttons));
+    }
+}