refactor: 重构项目为 MVC 架构并移除全局变量

- 将原有扁平目录结构重构为 MVC 分层架构：
  * src/core/: 核心业务逻辑（Model），完全独立于 UI 框架
  * src/ui/: 界面组件构建（View），负责纯视觉展示
  * src/controller/: 用户交互处理（Controller），连接数据与界面
  * src/utils/: 底层工具函数，专注于系统调用和字符串处理
- 引入 AppContext 结构体统一管理应用状态，替代原有的全局变量模式
- 重命名并重新组织头文件，按功能模块划分到对应子目录
- 更新 CMakeLists.txt 以适配新的目录结构
- 同步更新 README.md 文档，说明新的架构设计

src/core/app_context.c

@@ -0,0 +1,36 @@
+#include "core/app_context.h"
+#include <stdlib.h>
+
+// 创建应用上下文
+AppContext *create_app_context(void)
+{
+    AppContext *ctx = (AppContext *)malloc(sizeof(AppContext));
+    if (ctx)
+    {
+        init_string_list(&ctx->sys_paths);
+        init_string_list(&ctx->user_paths);
+    }
+    return ctx;
+}
+
+// 销毁应用上下文
+void destroy_app_context(AppContext *ctx)
+{
+    if (ctx)
+    {
+        clear_string_list(&ctx->sys_paths);
+        clear_string_list(&ctx->user_paths);
+        free(ctx);
+    }
+}
+
+// 获取应用上下文
+AppContext *get_app_context(Ihandle *ih)
+{
+    if (!ih)
+        return NULL;
+    Ihandle *dlg = IupGetDialog(ih);
+    if (!dlg)
+        return NULL;
+    return (AppContext *)IupGetAttribute(dlg, "APP_CONTEXT");
+}

src/core/path_manager.c

@@ -0,0 +1,82 @@
+#include "core/path_manager.h"
+#include "utils/os_env.h"
+#include <stdlib.h>
+#include <string.h>
+
+// 删除指定索引的路径项
+void path_manager_remove_at(StringList *list, int index)
+{
+    if (!list || index < 0 || index >= list->count)
+        return;
+    
+    free(list->items[index]);
+    for (int i = index; i < list->count - 1; i++)
+    {
+        list->items[i] = list->items[i + 1];
+    }
+    list->count--;
+}
+
+// 向上移动路径项
+void path_manager_move_up(StringList *list, int index)
+{
+    if (!list || index <= 0 || index >= list->count)
+        return;
+    
+    char *temp = list->items[index];
+    list->items[index] = list->items[index - 1];
+    list->items[index - 1] = temp;
+}
+
+// 向下移动路径项
+void path_manager_move_down(StringList *list, int index)
+{
+    if (!list || index < 0 || index >= list->count - 1)
+        return;
+    
+    char *temp = list->items[index];
+    list->items[index] = list->items[index + 1];
+    list->items[index + 1] = temp;
+}
+
+// 清理无效路径项
+int path_manager_clean(StringList *list)
+{
+    if (!list) return 0;
+    int removed_count = 0;
+
+    // 从后往前遍历，方便删除
+    for (int i = list->count - 1; i >= 0; i--)
+    {
+        char *item = list->items[i];
+        if (!item) continue;
+
+        int should_remove = 0;
+
+        // 1. 检查有效性
+        if (!is_path_valid(item))
+        {
+            should_remove = 1;
+        }
+        else
+        {
+            // 2. 检查重复 (检查当前项之前是否出现过)
+            for (int j = 0; j < i; j++)
+            {
+                char *prev_item = list->items[j];
+                if (prev_item && _stricmp(item, prev_item) == 0)
+                {
+                    should_remove = 1;
+                    break;
+                }
+            }
+        }
+
+        if (should_remove)
+        {
+            path_manager_remove_at(list, i);
+            removed_count++;
+        }
+    }
+    return removed_count;
+}

src/core/registry_service.c

@@ -0,0 +1,144 @@
+#include "core/registry_service.h"
+#include "utils/string_ext.h"
+#include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define REG_PATH_SYS L"SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Environment"
+#define REG_PATH_USER L"Environment"
+#define REG_VALUE L"Path"
+
+// 内部辅助函数：加载单个列表
+static int load_single_path(HKEY hKeyRoot, const wchar_t *regPath, StringList *list)
+{
+    clear_string_list(list);
+
+    HKEY hKey;
+    LONG res = RegOpenKeyExW(hKeyRoot, regPath, 0, KEY_READ, &hKey);
+    if (res != ERROR_SUCCESS)
+    {
+        return 0; // 失败
+    }
+
+    DWORD type, size;
+    res = RegQueryValueExW(hKey, REG_VALUE, NULL, &type, NULL, &size);
+    if (res == ERROR_SUCCESS)
+    {
+        wchar_t *buffer = (wchar_t *)malloc(size + 2);
+        if (buffer)
+        {
+            memset(buffer, 0, size + 2);
+            if (RegQueryValueExW(hKey, REG_VALUE, NULL, &type, (LPBYTE)buffer, &size) == ERROR_SUCCESS)
+            {
+                wchar_t *current = buffer;
+                wchar_t *next_semicolon = NULL;
+
+                while (*current)
+                {
+                    next_semicolon = wcschr(current, L';');
+                    if (next_semicolon)
+                        *next_semicolon = L'\0';
+
+                    if (wcslen(current) > 0)
+                    {
+                        char *utf8_str = wide_to_utf8(current);
+                        if (utf8_str)
+                        {
+                            add_string_list(list, utf8_str);
+                            free(utf8_str);
+                        }
+                    }
+
+                    if (next_semicolon)
+                        current = next_semicolon + 1;
+                    else
+                        break;
+                }
+            }
+            free(buffer);
+        }
+    }
+    RegCloseKey(hKey);
+    return 1; // 成功
+}
+
+// 加载系统环境变量路径
+int load_system_paths(StringList *list)
+{
+    return load_single_path(HKEY_LOCAL_MACHINE, REG_PATH_SYS, list);
+}
+
+// 加载用户环境变量路径
+int load_user_paths(StringList *list)
+{
+    return load_single_path(HKEY_CURRENT_USER, REG_PATH_USER, list);
+}
+
+// 内部辅助函数：保存单个列表
+static int save_single_path(HKEY hKeyRoot, const wchar_t *regPath, const StringList *list)
+{
+    if (!list) return 0;
+
+    // 计算大小
+    size_t total_len = 0;
+    for (int i = 0; i < list->count; i++)
+    {
+        if (list->items[i])
+        {
+            wchar_t *witem = utf8_to_wide(list->items[i]);
+            if (witem)
+            {
+                total_len += wcslen(witem) + 1;
+                free(witem);
+            }
+        }
+    }
+    total_len += 1;
+
+    wchar_t *buffer = (wchar_t *)malloc(total_len * sizeof(wchar_t));
+    if (!buffer)
+        return 0;
+
+    buffer[0] = L'\0';
+    for (int i = 0; i < list->count; i++)
+    {
+        if (list->items[i])
+        {
+            wchar_t *witem = utf8_to_wide(list->items[i]);
+            if (witem)
+            {
+                wcscat(buffer, witem);
+                if (i < list->count - 1)
+                    wcscat(buffer, L";");
+                free(witem);
+            }
+        }
+    }
+
+    HKEY hKey;
+    int success = 0;
+    if (RegOpenKeyExW(hKeyRoot, regPath, 0, KEY_WRITE, &hKey) == ERROR_SUCCESS)
+    {
+        DWORD size = (DWORD)((wcslen(buffer) + 1) * sizeof(wchar_t));
+        if (RegSetValueExW(hKey, REG_VALUE, 0, REG_EXPAND_SZ, (LPBYTE)buffer, size) == ERROR_SUCCESS)
+        {
+            success = 1;
+        }
+        RegCloseKey(hKey);
+    }
+
+    free(buffer);
+    return success;
+}
+
+// 保存系统环境变量路径
+int save_system_paths(const StringList *list)
+{
+    return save_single_path(HKEY_LOCAL_MACHINE, REG_PATH_SYS, list);
+}
+
+// 保存用户环境变量路径
+int save_user_paths(const StringList *list)
+{
+    return save_single_path(HKEY_CURRENT_USER, REG_PATH_USER, list);
+}