chore: snapshot editor work and restore tests

Key points:\n- restore the tests tree removed by bc47e6e\n- capture current editor workspace, scene, and docs reshuffle changes\n- keep local cloud.nvdb resources ignored from this commit

tests/Core/IO/test_resource_filesystem.cpp

@@ -0,0 +1,41 @@
+#include <gtest/gtest.h>
+#include <XCEngine/Core/IO/ResourceFileSystem.h>
+#include <XCEngine/Core/Containers/String.h>
+
+using namespace XCEngine::Resources;
+using namespace XCEngine::Containers;
+
+namespace {
+
+TEST(ResourceFileSystem, GetSingleton) {
+    ResourceFileSystem& fs = ResourceFileSystem::Get();
+    EXPECT_EQ(&fs, &ResourceFileSystem::Get());
+}
+
+TEST(ResourceFileSystem, Initialize) {
+    ResourceFileSystem fs;
+    fs.Initialize("test/path");
+    fs.Shutdown();
+}
+
+TEST(ResourceFileSystem, AddDirectory) {
+    ResourceFileSystem fs;
+    fs.Initialize("test/path");
+    
+    bool result = fs.AddDirectory("textures");
+    EXPECT_TRUE(result);
+    
+    fs.Shutdown();
+}
+
+TEST(ResourceFileSystem, Exists) {
+    ResourceFileSystem fs;
+    fs.Initialize("test/path");
+    
+    bool exists = fs.Exists("test.txt");
+    EXPECT_TRUE(exists);
+    
+    fs.Shutdown();
+}
+
+} // namespace