feat: 重构事件总线为可实例化架构并发布 1.3.0

- 新增 IShrinkEventBus、ShrinkEventBusBuilder 与 ShrinkEventBusInstance，支持独立 bus、异常策略、启动开关、类型校验和按 phase 派发
- 新增 SubscribeEvent 可释放订阅句柄与订阅快照接口，保留 EventBus 静态门面并委托到默认实例
- 重构监听列表为父子事件链共享锁与快照缓存，支持父事件监听子事件、跨父子数字优先级归并和防御性快照拷贝
- 优化 EventBase 元数据缓存、懒生成 EventId、派发快照挂接与对象池双重归还保护，移除旧 EventCache 热路径
- 恢复本地 ILPostProcessor 兜底并生成静态订阅注册表，避免共享 CodeGen 覆盖外程序集自动注册失效
- 改进事件查看器、Benchmark、README 与 CHANGELOG，并新增 Dispatch/Priority/Registration/Subscription 测试覆盖核心行为

BREAKING CHANGE: 移除 EventBase.GetListenerList()，int 数字优先级重载不再提供默认值，数字优先级 0 现在映射为 NORMAL。

Runtime/EventBusGeneratedRegistry.cs

@@ -0,0 +1,53 @@
+#nullable enable
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace ShrinkEventBus
+{
+    [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true)]
+    public sealed class EventBusStaticRegistryAttribute : Attribute
+    {
+        public EventBusStaticRegistryAttribute(params Type[] subscriberTypes)
+        {
+            SubscriberTypes = subscriberTypes ?? Array.Empty<Type>();
+        }
+
+        public Type[] SubscriberTypes { get; }
+    }
+
+    internal static class EventBusGeneratedRegistry
+    {
+        public static IReadOnlyList<Type> GetStaticSubscriberTypes()
+        {
+            var types = new List<Type>();
+            var seen = new HashSet<Type>();
+            foreach (var assembly in AppDomain.CurrentDomain.GetAssemblies())
+            {
+                object[] attributes;
+                try
+                {
+                    attributes = assembly.GetCustomAttributes(typeof(EventBusStaticRegistryAttribute), false);
+                }
+                catch
+                {
+                    continue;
+                }
+
+                foreach (var attribute in attributes.OfType<EventBusStaticRegistryAttribute>())
+                {
+                    foreach (var subscriberType in attribute.SubscriberTypes ?? Array.Empty<Type>())
+                    {
+                        if (subscriberType == null || !seen.Add(subscriberType))
+                            continue;
+
+                        types.Add(subscriberType);
+                    }
+                }
+            }
+
+            return types;
+        }
+    }
+}