Add initial documentation and structure for DorkNet project

- Create README.md for project overview and setup instructions
- Add admin-ui/README.md for admin UI details and development setup
- Introduce client-mod/README.md explaining the MelonLoader mod functionality
- Establish docker/README.md for Docker setup and configuration
- Create docs/README.md to index project documentation
- Implement advanced-setup.md for Docker stack configuration
- Document architecture in architecture.md
- Provide easy-setup.md for hosting instructions
- Add FAQ.md for common questions and legal considerations
- Create joining-a-server.md for player connection instructions
- Establish troubleshooting.md for common issues and resolutions
- Introduce easy-app/README.md for the unified desktop application
- Add server/README.md for ASP.NET Core backend details
- Document tools/README.md for CLI helper scripts

server/README.md

@@ -0,0 +1,57 @@
+# server/
+
+The ASP.NET Core backend.
+
+Built two ways:
+- **Standalone Postgres-backed** for advanced mode (Docker), via
+  `dotnet run` or the `dorknet-server` container.
+- **In-process SQLite-backed** for the Easy desktop app, hosted as a
+  library inside `easy-app/`.
+
+## Code layout (TBC)
+
+```
+server/
+├── Controllers/    HTTP endpoints, sliced by subdomain → service
+├── Services/       Business logic (presence, notifications, levels, ...)
+├── Hubs/           SignalR NotifyHub
+├── Data/           DbContext + EntityFramework entity classes
+├── Auth/           JWT issuance, Photon CustomAuth handler
+├── Middleware/     SubdomainRouter, request logging, error handling
+└── Program.cs      Boot: migrations, seeds, canonical overrides, DI
+```
+
+## Building
+
+```bash
+dotnet build -c Release
+dotnet run                                  # localhost:5000
+```
+
+## Provider switch
+
+The DbContext is provider-agnostic. `appsettings` picks one:
+
+```jsonc
+{
+  "ConnectionStrings": {
+    // Postgres for advanced mode
+    "Default": "Host=localhost;Database=dorknet;Username=dorknet;Password=..."
+    // OR SQLite for easy mode
+    // "Default": "Data Source=dorknet.db"
+  },
+  "Database": {
+    "Provider": "Postgres"  // or "Sqlite"
+  }
+}
+```
+
+Easy app boots with `Provider=Sqlite` baked in; standalone defaults to
+`Provider=Postgres`.
+
+## See also
+
+- [docs/architecture.md](../docs/architecture.md) — request flow,
+  subdomain routing, Photon relationship
+- [docs/advanced-setup.md](../docs/advanced-setup.md) — production setup
+- [CONTRIBUTING.md](../CONTRIBUTING.md) — style + PR rules