零开销抽象

docs/CORE_GUIDE.md

@@ -407,7 +407,7 @@ auto policy = property_synchronization<Device>(
 );
 ```
 
-The schema remains the same; only the instance lock topology changes.
+The schema remains the same; only that instance uses an override lock topology. Default instances share one resolved topology per type, so the default plan is not re-resolved for every object.
 
 ## 15. Inspect resolved synchronization
 
@@ -628,7 +628,7 @@ struct Device : Property_Object<Device, No_Lock_Policy> {
 };
 ```
 
-`No_Lock_Policy` uses `Null_Shared_Mutex`; it removes real mutual exclusion and should only be selected when external ownership guarantees make that correct.
+`No_Lock_Policy` uses `Null_Shared_Mutex`; it removes real mutual exclusion and should only be selected when external ownership guarantees make that correct. Its default managed-object path stores no mutex array and performs no per-instance heap allocation for synchronization. A custom `Property_Synchronization` may still allocate a compact override topology because computed-property synchronization-domain checks must preserve the selected per-instance layout.
 
 ## 23. Raw object access
 

docs/CORE_GUIDE.zh-CN.md

@@ -407,7 +407,7 @@ auto policy = property_synchronization<Device>(
 );
 ```
 
-Schema 本身不变，只改变该实例的 lock topology。
+Schema 本身不变，只有这个实例使用覆盖后的 lock topology。默认实例按类型共享一份解析结果，因此不会为每个对象重复解析默认同步计划。
 
 ## 15. 查看解析后的同步拓扑
 
@@ -628,7 +628,7 @@ struct Device : Property_Object<Device, No_Lock_Policy> {
 };
 ```
 
-`No_Lock_Policy` 使用 `Null_Shared_Mutex`，它取消真实互斥；只有外部所有权规则能够保证正确性时才应该使用。
+`No_Lock_Policy` 使用 `Null_Shared_Mutex`，它取消真实互斥；只有外部所有权规则能够保证正确性时才应该使用。默认 managed-object 路径不保存 mutex 数组，也不会为同步状态产生每实例堆分配。显式使用自定义 `Property_Synchronization` 时仍可能分配一份紧凑覆盖 topology，因为 computed property 的同步域检查必须保留该实例选择的布局。
 
 ## 23. Raw Object Access
 

docs/DESIGN.md

@@ -72,8 +72,9 @@ This is the structural definition of the type.
 
 `Property_Object<T>` provides:
 
-- resolved lock-slot topology;
-- per-instance mutex storage;
+- a type-shared resolved default lock-slot topology;
+- per-instance mutex storage only when the selected lock policy requires real mutexes;
+- a compact per-instance topology only for explicit synchronization overrides;
 - managed typed reads and writes;
 - capability views;
 - static and runtime multi-property guards;
@@ -84,7 +85,7 @@ This is instance behavior, not schema identity.
 
 ### 3.3 Design rule
 
-Do not move instance state into the schema, and do not make schema metadata depend on one particular instance-management policy.
+Do not move mutable instance synchronization state into the schema, and do not make schema metadata depend on one particular instance-management policy. Immutable topology derived from the type-level default plan may be shared across all instances of that type.
 
 A future user may want to describe a large number of plain objects without paying per-object synchronization cost. The architecture should continue to leave that possibility open.
 

docs/DESIGN.zh-CN.md

@@ -72,8 +72,9 @@ Structive 把类型级描述和实例级管理分开。
 
 `Property_Object<T>` 提供：
 
-- 解析后的 lock slot 拓扑；
-- 每实例 mutex 存储；
+- 同一类型共享的默认解析 lock slot 拓扑；
+- 只有真实锁策略才需要的每实例 mutex 存储；
+- 只有显式同步覆盖实例才持有的紧凑 topology；
 - managed typed read/write；
 - capability view；
 - 静态与运行时多属性 guard；
@@ -84,7 +85,7 @@ Structive 把类型级描述和实例级管理分开。
 
 ### 3.3 设计约束
 
-不要把实例状态塞进 Schema，也不要让 Schema 必须依赖某一种特定的实例管理策略。
+不要把可变的实例同步状态塞进 Schema，也不要让 Schema 必须依赖某一种特定的实例管理策略。由类型级默认同步计划推导出的不可变 topology 可以由同类型所有实例共享。
 
 以后完全可能有用户只想描述大量普通对象，却不愿意为每个对象承担同步状态成本。当前架构应该持续保留这种可能性。