feat: enhance @PostConstruct with order and @Qualifier for fields

- Add value() to @PostConstruct for execution order control
- Allow @Qualifier on fields for use with @Inject
- Sort @PostConstruct methods by inheritance depth then order value

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

src/main/java/com/imyeyu/inject/annotation/PostConstruct.java

@@ -13,4 +13,11 @@ import java.lang.annotation.Target;
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)
 public @interface PostConstruct {
+
+	/**
+	 * 执行顺序，数值越小越先执行，默认为 0
+	 *
+	 * @return 执行顺序
+	 */
+	int value() default 0;
 }

src/main/java/com/imyeyu/inject/annotation/Qualifier.java

@@ -10,7 +10,7 @@ import java.lang.annotation.Target;
  *
  * @author 夜雨
  */
-@Target(ElementType.PARAMETER)
+@Target({ElementType.PARAMETER, ElementType.FIELD})
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Qualifier {