launcher: compress game folders to ZAR

src/common/archive.h

@@ -5,6 +5,7 @@
 
 #include <cstdint>
 #include <filesystem>
+#include <functional>
 #include <memory>
 #include <vector>
 
@@ -45,6 +46,12 @@ private:
 // Accepts either a host archive filename or a virtual path inside the archive.
 [[nodiscard]] std::shared_ptr<ArchiveReader> OpenArchive(const std::filesystem::path& path);
 
+// Packs a host directory into a new ZArchive outside it. progress gets 0 < done <= total and
+// returns false to cancel. A failed or cancelled pack removes the partial archive.
+[[nodiscard]] bool PackArchive(const std::filesystem::path& directory,
+                               const std::filesystem::path& archive,
+                               const std::function<bool(uint64_t done, uint64_t total)>& progress);
+
 } // namespace Common
 
 #endif /* KYTY_COMMON_ARCHIVE_H_ */