refactor: 重构枚举类并统一模式定义

- 新增 Mode 枚举类，用于统一定义程序的运行和调试模式- 删除 VMMode 枚举类，使用新的 Mode 枚举替代
- 通过重构简化代码结构，提高代码可维护性

src/main/java/org/jcnc/snow/common/Mode.java

@@ -0,0 +1,20 @@
+package org.jcnc.snow.common;
+
+/**
+ * 程序的运行/调试模式枚举。
+ * <ul>
+ *   <li>RUN：运行模式</li>
+ *   <li>DEBUG：调试模式</li>
+ * </ul>
+ */
+public enum Mode {
+    /**
+     * 运行模式。
+     */
+    RUN,
+
+    /**
+     * 调试模式。
+     */
+    DEBUG
+}

src/main/java/org/jcnc/snow/vm/engine/VMMode.java

@@ -1,19 +0,0 @@
-package org.jcnc.snow.vm.engine;
-
-/**
- * The VMMode enum defines the different operational modes of the virtual machine.
- * <p>This class is used to distinguish the behavior of the virtual machine in different states, with each mode corresponding to a different operational logic.</p>
- */
-public enum VMMode {
-    /**
-     * Run Mode: The virtual machine executes instructions in the normal execution flow.
-     * <p>In this mode, the virtual machine processes instructions and performs related calculations.</p>
-     */
-    RUN,
-
-    /**
-     * Debug Mode: The virtual machine outputs debug information during execution.
-     * <p>This mode is used for debugging the virtual machine, allowing developers to view detailed information such as the execution state, local variables, and more.</p>
-     */
-    DEBUG,
-}