docs(session): document creation ownership boundaries

docs/core-data-structures/session.zh.md

@@ -353,13 +353,14 @@ interface SurfaceFoldResult {
 
 ## `Session` 公共 API
 
-去除方法体的声明与源码中的普通类保持同步，覆盖其公共构造函数、状态访问器、追加边界和历史投影。存储操作仍由生成的 [`ctx.sessions` 服务目录](../cordis-catalog/services.md#ctxsessions--sessionstore)记录。
+去除方法体的声明与源码中的普通类保持同步，覆盖其脱离态工厂、状态访问器、追加边界和历史投影。存储操作仍由生成的 [`ctx.sessions` 服务目录](../cordis-catalog/services.md#ctxsessions--sessionstore)记录。
 
 ```ts public-api
 /**
  * An event-sourced session: an append-only log of {@link SessionEvent}s.
  *
- * Plain class (not a Service) — create instances via `ctx.sessions.create()`.
+ * Plain class (not a Service) — create live instances via
+ * `ctx.sessions.create()` and detached instances via {@link create}.
  * Seeding with an existing event log replays/forks a session.
  * @typert object
  */
@@ -402,7 +403,15 @@ declare class Session {
    * holds an ordinary published write.
    */
   readonly firstLiveSeq: number;
-  constructor(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader);
+  /**
+   * Create a detached session by validating and snapshotting borrowed seed
+   * events and storage metadata.
+   * @param id - session identity.
+   * @param seed - optional borrowed replay or fork events.
+   * @param header - optional borrowed storage metadata.
+   * @returns a detached session.
+   */
+  static create(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader): Session;
   /**
    * An immutable snapshot of the append-only event log. The snapshot is reused
    * until the next append; a previously returned array does not grow later.