refactor: 根包由 com.bestsch.bschclassmanage 重命名为 com.yunhai.bschclassmanage

- git mv src/main/java/com/bestsch/bschclassmanage -> src/main/java/com/yunhai/bschclassmanage
- 255 个 Java 文件的 package/import 同步替换为 com.yunhai.bschclassmanage
- pom.xml 项目 groupId 设为 com.yunhai（与外部依赖 com.bestsch:bsch-* 无关，未改动）
- IDE 缓存 workspace.xml 路径同步更新（外部依赖坐标 com.bestsch:bsch-* 保持不动）

src/main/java/com/yunhai/bschclassmanage/model/entityField/EntityFieldNames.java

@@ -0,0 +1,68 @@
+package com.yunhai.bschclassmanage.model.entityField;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+/**
+ * 实体类字段名称常量定义。
+ * <p>
+ * 集中管理所有实体类的公共字段名，避免硬编码字符串，
+ * 便于统一修改和 IDE 自动补全。
+ * </p>
+ *
+ * @author YourName
+ * @since 2026-07-10
+ *//**
+ * 实体类字段名称常量定义。
+ * <p>
+ * 集中管理所有实体类的公共字段名，避免硬编码字符串，
+ * 便于统一修改和 IDE 自动补全。
+ * </p>
+ *
+ * @author YourName
+ * @since 2026-07-10
+ */
+public final class EntityFieldNames {
+
+    // ==================== 基础字段 ====================
+    public static final String id = "id";
+    public static final String account = "account";
+    public static final String idCard = "idCard";
+    public static final String name = "name";
+    public static final String code = "code";
+    public static final String sort = "sort";
+    public static final String year = "year";
+    public static final String enrollYear = "enrollYear";
+
+    // ==================== 关联字段 ====================
+    public static final String gradeId = "gradeId";
+    public static final String groupId = "groupId";
+    public static final String schId = "schId";
+    public static final String classId = "classId";
+    public static final String schSystemId = "schSystemId";
+
+    public static final String teaId = "teaId";
+    public static final String stuId = "stuId";
+
+    // ==================== 状态字段 ====================
+    public static final String status = "status";
+    public static final String abnormalStatus = "abnormalStatus";
+    public static final String transferStatus = "transferStatus";
+    public static final String graduate = "graduate";
+
+    // ==================== 审计字段 ====================
+    public static final String createDate = "createDate";
+    public static final String updateDate = "updateDate";
+    public static final String createUserId = "createUserId";
+    public static final String updateUserId = "updateUserId";
+
+    /**
+     * 私有构造函数，防止实例化。
+     */
+    private EntityFieldNames() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+}