refactor: simplify ConfigLoader and enhance ConfigRepresenter

- Bump version to 0.0.2 and update timi-io dependency
- Refactor ConfigLoader with cleaner SnakeYAML integration
- Add LoaderOptions security settings (recursion limit, alias limit, size limit)
- Enhance ConfigRepresenter to skip null values and improve enum serialization
- Remove RawMapper inner class and rawMappingList in favor of direct field reflection
- Simplify converter mechanism with cleaner serialize/deserialize flow
- Update tests to match new simplified API
- Add .claude and temp files to .gitignore

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/main/java/com/imyeyu/config/ConfigRepresenter.java

@@ -1,18 +1,53 @@
 package com.imyeyu.config;
 
 import org.yaml.snakeyaml.DumperOptions;
+import org.yaml.snakeyaml.introspector.Property;
+import org.yaml.snakeyaml.nodes.NodeTuple;
 import org.yaml.snakeyaml.nodes.Tag;
 import org.yaml.snakeyaml.representer.Representer;
 
 /**
+ * 自定义 Representer - SnakeYAML 序列化增强
+ * <ul>
+ *     <li>跳过 null 值字段，保持 YAML 简洁</li>
+ *     <li>禁用类型标签，输出纯净的 YAML</li>
+ *     <li>枚举序列化为字符串</li>
+ * </ul>
+ *
  * @author 夜雨
- * @version 2024-05-01 14:03
+ * @since 2026-01-12 12:02
  */
 public class ConfigRepresenter extends Representer {
 
 	public ConfigRepresenter(DumperOptions options) {
 		super(options);
-
+		// null 值表示为空字符串
 		this.nullRepresenter = data -> representScalar(Tag.NULL, "");
+		// 枚举转字符串（不带类型标签）
+		this.representers.put(Enum.class, data -> {
+			Enum<?> enumValue = (Enum<?>) data;
+			return representScalar(Tag.STR, enumValue.name());
+		});
+	}
+
+	@Override
+	protected NodeTuple representJavaBeanProperty(Object javaBean, Property property, Object propertyValue, Tag customTag) {
+		// 跳过 null 值，保持 YAML 简洁
+		if (propertyValue == null) {
+			return null;
+		}
+		return super.representJavaBeanProperty(javaBean, property, propertyValue, customTag);
+	}
+
+	@Override
+	protected org.yaml.snakeyaml.nodes.MappingNode representJavaBean(java.util.Set<Property> properties, Object javaBean) {
+		Class<?> clazz = javaBean.getClass();
+		// 对于非 Java 标准库的类，使用 MAP 标签而不是类名标签
+		if (!clazz.getName().startsWith("java.") && !clazz.getName().startsWith("javax.")) {
+			if (this.classTags.get(clazz) == null) {
+				this.addClassTag(clazz, Tag.MAP);
+			}
+		}
+		return super.representJavaBean(properties, javaBean);
 	}
 }