feat: 实现Containers、Memory、Threading核心模块及单元测试

- Containers: String, Array, HashMap 容器实现及测试
- Memory: Allocator, LinearAllocator, PoolAllocator, ProxyAllocator, MemoryManager 实现及测试
- Threading: Mutex, SpinLock, ReadWriteLock, Thread, Task, TaskSystem 实现及测试
- 修复Windows平台兼容性: _aligned_malloc, std::hash特化
- 修复构建错误和测试用例问题

tests/memory/test_linear_allocator.cpp

@@ -0,0 +1,77 @@
+#include <gtest/gtest.h>
+#include <XCEngine/Memory/LinearAllocator.h>
+#include <cstring>
+
+using namespace XCEngine::Memory;
+
+namespace {
+
+TEST(LinearAllocator, Allocate) {
+    LinearAllocator allocator(1024);
+    
+    void* ptr = allocator.Allocate(64);
+    ASSERT_NE(ptr, nullptr);
+    EXPECT_EQ(allocator.GetUsedSize(), 64u);
+}
+
+TEST(LinearAllocator, Allocate_Aligned) {
+    LinearAllocator allocator(1024);
+    
+    void* ptr = allocator.Allocate(64, 16);
+    ASSERT_NE(ptr, nullptr);
+    
+    uintptr_t addr = reinterpret_cast<uintptr_t>(ptr);
+    EXPECT_EQ(addr % 16, 0u);
+}
+
+TEST(LinearAllocator, Clear) {
+    LinearAllocator allocator(1024);
+    
+    allocator.Allocate(64);
+    EXPECT_EQ(allocator.GetUsedSize(), 64u);
+    
+    allocator.Clear();
+    EXPECT_EQ(allocator.GetUsedSize(), 0u);
+}
+
+TEST(LinearAllocator, Marker) {
+    LinearAllocator allocator(1024);
+    
+    allocator.Allocate(64);
+    void* marker = allocator.GetMarker();
+    
+    allocator.Allocate(32);
+    EXPECT_EQ(allocator.GetUsedSize(), 96u);
+    
+    allocator.SetMarker(marker);
+    EXPECT_EQ(allocator.GetUsedSize(), 64u);
+}
+
+TEST(LinearAllocator, AllocateMultiple) {
+    LinearAllocator allocator(1024);
+    
+    allocator.Allocate(100);
+    allocator.Allocate(200);
+    allocator.Allocate(300);
+    
+    EXPECT_GE(allocator.GetUsedSize(), 600u);
+}
+
+TEST(LinearAllocator, OutOfMemory) {
+    LinearAllocator allocator(200);
+    
+    void* ptr1 = allocator.Allocate(50, 8);
+    void* ptr2 = allocator.Allocate(50, 8);
+    ASSERT_NE(ptr1, nullptr);
+    ASSERT_NE(ptr2, nullptr);
+    
+    void* ptr3 = allocator.Allocate(100, 8);
+    EXPECT_EQ(ptr3, nullptr);
+}
+
+TEST(LinearAllocator, GetCapacity) {
+    LinearAllocator allocator(512);
+    EXPECT_EQ(allocator.GetCapacity(), 512u);
+}
+
+} // namespace