build: 迁移项目构建系统至 CMake

- 新增 CMakeLists.txt 文件，定义项目构建规则、依赖和编译选项。
- 更新 README.md 文档，推荐使用 CMake 进行构建，并说明新旧构建方式。
- 保留原有的 Makefile 支持以保持向后兼容。

CMakeLists.txt

@@ -0,0 +1,55 @@
+cmake_minimum_required(VERSION 3.10)
+project(PathEditor C)
+
+# Compile flags and definitions
+add_compile_options(-Wall -O2 -fexec-charset=UTF-8)
+add_compile_definitions(_WIN32 UNICODE _UNICODE)
+
+# Include directories
+include_directories(
+    ${CMAKE_CURRENT_SOURCE_DIR}/include
+    ${CMAKE_CURRENT_SOURCE_DIR}/libs/iup-3.31_Win64_dllw6_lib/include
+)
+
+# Source files
+set(SOURCES
+    src/main.c
+    src/utils.c
+    src/registry.c
+    src/callbacks.c
+    src/ui.c
+    src/globals.c
+)
+
+# Resource file
+set(RESOURCES
+    ico/resources.rc
+)
+
+# Library directories
+link_directories(
+    ${CMAKE_CURRENT_SOURCE_DIR}/libs/iup-3.31_Win64_dllw6_lib
+)
+
+# Create WIN32 executable (automatically adds -mwindows and handles .rc files)
+add_executable(${PROJECT_NAME} WIN32 ${SOURCES} ${RESOURCES})
+
+# Link libraries
+target_link_libraries(${PROJECT_NAME} PRIVATE
+    iup
+    iupcd
+    gdi32
+    comdlg32
+    comctl32
+    uuid
+    ole32
+    advapi32
+)
+
+# Copy DLLs to the build directory after building
+add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_directory
+    "${CMAKE_CURRENT_SOURCE_DIR}/libs/iup-3.31_Win64_dllw6_lib/"
+    "$<TARGET_FILE_DIR:${PROJECT_NAME}>"
+    COMMENT "Copying DLLs to build directory..."
+)