refactor: optimize string concatenation and add startup statistics

- Replace string concatenation with .formatted() method for better readability
- Add StartupStatistics class to track initialization metrics
- Add detailed startup logging with timing information
  - Scan time
  - IOC time
  - Injection time
  - PostConstruct time
  - Total startup time
- Add banner output support (banner.txt or defBanner.txt)
- Add @Lazy annotation support for lazy initialization

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

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

@@ -6,11 +6,11 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * 标记用于依赖注入的构造器
+ * 标记用于依赖注入的构造器或字段
  *
  * @author 夜雨
  */
-@Target(ElementType.CONSTRUCTOR)
+@Target({ElementType.CONSTRUCTOR, ElementType.FIELD})
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Inject {
 }

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

@@ -0,0 +1,17 @@
+package com.imyeyu.inject.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * 标记 Bean 为懒加载
+ * 等同于 @Scope(value = ScopeType.SINGLETON, lazy = true)
+ *
+ * @author 夜雨
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Lazy {
+}

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

@@ -18,4 +18,11 @@ public @interface Scope {
      * 作用域类型
      */
     ScopeType value() default ScopeType.SINGLETON;
+
+    /**
+     * 是否懒加载（仅对 SINGLETON 作用域有效）
+     * true - 首次使用时才创建
+     * false - 启动时立即创建（默认）
+     */
+    boolean lazy() default false;
 }