Add initial project backend structure with Docker support and configuration files. Added some useful features such as async requests, automatically adding card by message from chat etc

Signed-off-by: Dmitrii <computer@yawaflua.tech>

Took 9 minutes

src/backend/SpMega.Backend/Dockerfile

@@ -0,0 +1,23 @@
+FROM mcr.microsoft.com/dotnet/aspnet:10.0 AS base
+USER $APP_UID
+WORKDIR /app
+EXPOSE 8080
+EXPOSE 8081
+
+FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
+ARG BUILD_CONFIGURATION=Release
+WORKDIR /src
+COPY ["SpMega.Backend/SpMega.Backend.csproj", "SpMega.Backend/"]
+RUN dotnet restore "SpMega.Backend/SpMega.Backend.csproj"
+COPY . .
+WORKDIR "/src/SpMega.Backend"
+RUN dotnet build "./SpMega.Backend.csproj" -c $BUILD_CONFIGURATION -o /app/build
+
+FROM build AS publish
+ARG BUILD_CONFIGURATION=Release
+RUN dotnet publish "./SpMega.Backend.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false
+
+FROM base AS final
+WORKDIR /app
+COPY --from=publish /app/publish .
+ENTRYPOINT ["dotnet", "SpMega.Backend.dll"]