feat(themes): 添加 JsonbTypeHandler 支持 themeTag 字段

新增 PostgreSQL JSONB 类型处理器，使 themeTag 字段可直接映射到数据库 JSONB 列。

yolo-framework/yolo-spring-boot-starter-mybatis/src/main/java/com/yolo/keyboard/framework/mybatis/core/type/JsonbTypeHandler.java

@@ -0,0 +1,56 @@
+package com.yolo.keyboard.framework.mybatis.core.type;
+
+import cn.hutool.json.JSONUtil;
+import org.apache.ibatis.type.BaseTypeHandler;
+import org.apache.ibatis.type.JdbcType;
+import org.apache.ibatis.type.MappedTypes;
+import org.postgresql.util.PGobject;
+
+import java.sql.CallableStatement;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * PostgreSQL jsonb 类型处理器
+ *
+ * @author ziin
+ */
+@MappedTypes(Object.class)
+public class JsonbTypeHandler extends BaseTypeHandler<Object> {
+
+    private static final String JSONB_TYPE = "jsonb";
+
+    @Override
+    public void setNonNullParameter(PreparedStatement ps, int i, Object parameter, JdbcType jdbcType) throws SQLException {
+        PGobject pgObject = new PGobject();
+        pgObject.setType(JSONB_TYPE);
+        pgObject.setValue(JSONUtil.toJsonStr(parameter));
+        ps.setObject(i, pgObject);
+    }
+
+    @Override
+    public Object getNullableResult(ResultSet rs, String columnName) throws SQLException {
+        String value = rs.getString(columnName);
+        return parseJson(value);
+    }
+
+    @Override
+    public Object getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
+        String value = rs.getString(columnIndex);
+        return parseJson(value);
+    }
+
+    @Override
+    public Object getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
+        String value = cs.getString(columnIndex);
+        return parseJson(value);
+    }
+
+    private Object parseJson(String value) {
+        if (value == null || value.isEmpty()) {
+            return null;
+        }
+        return JSONUtil.parse(value);
+    }
+}