build: 迁移构建系统至CMake，重写README文档

将GNU Makefile构建系统迁移到CMake 3.15+，新增CLAUDE.md项目指南，
重写README.md补充项目结构、工作原理和详细构建说明。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CMakeLists.txt

@@ -0,0 +1,33 @@
+cmake_minimum_required(VERSION 3.15)
+project(PathEditor LANGUAGES C)
+
+set(IUP_DIR "${CMAKE_SOURCE_DIR}/libs/iup-3.31_Win64_dllw6_lib")
+
+add_executable(PathEditor
+    src/main.c
+    src/utils.c
+    src/registry.c
+    src/callbacks.c
+    ico/resources.rc
+)
+
+target_include_directories(PathEditor PRIVATE
+    ${IUP_DIR}/include
+    include
+)
+
+target_link_directories(PathEditor PRIVATE ${IUP_DIR})
+
+target_link_libraries(PathEditor
+    iup iupcd gdi32 comdlg32 comctl32 uuid ole32 advapi32
+)
+
+target_compile_definitions(PathEditor PRIVATE _WIN32 UNICODE _UNICODE)
+
+target_compile_options(PathEditor PRIVATE -Wall -O2 -fexec-charset=UTF-8)
+
+target_link_options(PathEditor PRIVATE -mwindows)
+
+set_target_properties(PathEditor PROPERTIES
+    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/bin"
+)