Thin Windows entry, preview shell, and platform legacy state

src/platform_legacy/legacy_platform_state.cpp

@@ -0,0 +1,30 @@
+#include "pch.h"
+#include "platform_legacy/legacy_platform_state.h"
+
+#include "app.h"
+
+namespace pp::platform::legacy {
+namespace {
+
+struct RetainedLegacyStoragePaths final {
+    pp::platform::PlatformStoragePaths storage_paths;
+};
+
+}
+
+[[nodiscard]] const pp::platform::PlatformStoragePaths& active_legacy_storage_paths()
+{
+    static RetainedLegacyStoragePaths state = [] {
+        RetainedLegacyStoragePaths retained;
+        retained.storage_paths = {
+            App::I->data_path,
+            App::I->work_path,
+            App::I->rec_path,
+            App::I->tmp_path,
+        };
+        return retained;
+    }();
+    return state.storage_paths;
+}
+
+}