Initial commit

Add Discord Archive Manager project with:
- Entity Framework Core data models for Discord exports
- JSON import service for processing Discord chat exports
- Archive service for managing imported data
- Docker configuration for containerized deployment

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,22 @@
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
+WORKDIR /src
+
+# Copy csproj and restore
+COPY src/DiscordArchiveManager/DiscordArchiveManager.csproj src/DiscordArchiveManager/
+RUN dotnet restore src/DiscordArchiveManager/DiscordArchiveManager.csproj
+
+# Copy everything else and build
+COPY . .
+WORKDIR /src/src/DiscordArchiveManager
+RUN dotnet publish -c Release -o /app/publish
+
+# Runtime image
+FROM mcr.microsoft.com/dotnet/runtime:8.0
+WORKDIR /app
+
+# Create directories for volumes
+RUN mkdir -p /app/input /app/archive /app/images
+
+COPY --from=build /app/publish .
+
+ENTRYPOINT ["dotnet", "DiscordArchiveManager.dll"]