Windows support: portable local server launch + clean quit, %APPDATA% data dir, Win32 libs, MinGW/MSVC build docs

client/LocalServer.h

@@ -0,0 +1,41 @@
+#pragma once
+// Runs safari_server next to the client executable for "Host & Play".
+// The child's stdin is a pipe: stop() sends the console command `quit` so the
+// server saves and exits cleanly on every platform (Windows has no SIGTERM),
+// and only kills it if it does not exit in time. Its output goes to a log file.
+
+#include <cstdint>
+#include <filesystem>
+#include <string>
+
+namespace bs {
+
+// Per-user data folder: %APPDATA%\brandling-safari on Windows,
+// $XDG_DATA_HOME/brandling-safari or ~/.local/share/brandling-safari elsewhere
+// (the server uses the same folder for world.db). Created if missing.
+std::filesystem::path userDataDir();
+std::filesystem::path executableDir();
+
+class LocalServer {
+public:
+    LocalServer() = default;
+    LocalServer(const LocalServer&) = delete;
+    LocalServer& operator=(const LocalServer&) = delete;
+    ~LocalServer() { stop(); }
+
+    // Starts `safari_server --port <port> --name <name>`; false + `error` on failure.
+    bool start(uint16_t port, const std::string& name, std::string& error);
+    void stop();
+    bool running() const;
+
+private:
+#if defined(_WIN32)
+    void* process_ = nullptr;  // HANDLE
+    void* stdin_ = nullptr;    // HANDLE (write end)
+#else
+    int pid_ = -1;
+    int stdin_ = -1;
+#endif
+};
+
+}  // namespace bs