wider migration from old starter

README.md

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+# StarterNG
+
+Launcher for the MaSzyna train simulator, written in C# with Avalonia.
+
+## Building a native (NativeAOT) build
+
+The project publishes as a self-contained NativeAOT binary — no .NET runtime is
+needed on the target machine. The commands below are the same ones CI runs, see
+[`.github/workflows/dotnet.yml`](.github/workflows/dotnet.yml).
+
+Requirements:
+
+- .NET SDK 9
+- Linux: a native toolchain and zlib headers — `sudo apt install clang zlib1g-dev`
+  (Debian/Ubuntu) or `sudo dnf install clang zlib-devel` (Fedora)
+- Windows: the Visual Studio C++ build tools (Desktop development with C++)
+
+Restore for the target runtime first, then publish:
+
+```sh
+dotnet restore StarterNG/StarterNG.csproj -r linux-x64
+
+dotnet publish StarterNG/StarterNG.csproj \
+    -c Release -r linux-x64 --self-contained true --no-restore \
+    -p:PublishAot=true -p:PublishTrimmed=true \
+    -o publish/linux-x64
+```
+
+For a Windows build swap both `linux-x64` occurrences for `win-x64` (and the
+line continuations for PowerShell backticks). NativeAOT does not cross-compile,
+so the Windows package has to be built on Windows and the Linux one on Linux —
+that is why CI uses a `windows-2022` and an `ubuntu-22.04` runner.
+
+The output directory is the whole distributable: the `Starter` executable, the
+Skia/HarfBuzz native libraries and `startercfg/` with the translations and the
+default key bindings. The `.dbg` (or `.pdb`) file next to it is debug symbols and
+can be dropped from a release. Trim/AOT analysis warnings during the publish are
+expected and do not fail the build.
+
+CI builds both runtimes on every push and pull request to `main` and `staging`,
+and on manual dispatch. Pushes additionally replace a rolling pre-release with
+the packaged artifacts — tagged `latest` for `main` and `staging` for `staging`.
+
+## Development build
+
+```sh
+dotnet build StarterNG/StarterNG.csproj
+```