Land the package filesystem shell: streaming atomic package_io, journaled rollback carve-out, asymmetric platform pickers

src/shell/package/package_pickers.h

@@ -0,0 +1,21 @@
+// shell/package/package_pickers — the two package file pickers, and they are
+// deliberately asymmetric: import rides REAPER's own read picker
+// (GetUserFileNameForRead, both platforms); export goes native — Win32
+// GetSaveFileNameW / SWELL BrowseForSaveFile — because the always-present REAPER
+// surface offers no save picker. Do not symmetrize; the rationale is in the TU.
+
+#pragma once
+
+#include <string>
+
+namespace reasampler {
+
+// REAPER's read picker. True with outAbsPath set iff the user chose a file.
+bool pickPackageForImport(std::string& outAbsPath);
+
+// Native save picker, pre-filled with suggestedFileName (a bare name, e.g.
+// "MyBank.rsbank"). True with outAbsPath set iff the user chose a destination; the
+// dialog's own overwrite confirm has already run by then.
+bool pickPackageSavePath(const std::string& suggestedFileName, std::string& outAbsPath);
+
+}  // namespace reasampler