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.Web/Dockerfile

@@ -0,0 +1,24 @@
+# Stage 1: Build
+FROM mcr.microsoft.com/dotnet/sdk:10.0-noble AS build
+WORKDIR /src
+
+# Copy projects
+COPY ["src/GmRelay.Web/GmRelay.Web.csproj", "src/GmRelay.Web/"]
+COPY ["src/GmRelay.Shared/GmRelay.Shared.csproj", "src/GmRelay.Shared/"]
+COPY ["src/GmRelay.ServiceDefaults/GmRelay.ServiceDefaults.csproj", "src/GmRelay.ServiceDefaults/"]
+
+# Restore
+RUN dotnet restore "src/GmRelay.Web/GmRelay.Web.csproj"
+
+# Copy all and build
+COPY src/ src/
+WORKDIR /src/src/GmRelay.Web
+RUN dotnet publish "GmRelay.Web.csproj" -c Release -o /app/publish /p:UseAppHost=false
+
+# Stage 2: Runtime
+FROM mcr.microsoft.com/dotnet/aspnet:10.0-noble AS final
+WORKDIR /app
+COPY --from=build /app/publish .
+ENV ASPNETCORE_URLS=http://+:8080
+EXPOSE 8080
+ENTRYPOINT ["dotnet", "GmRelay.Web.dll"]