Merge branch 'master' into codex/session-directory-layout

docs/core-data-structures/persistence.md

@@ -1,5 +1,7 @@
 # Session Persistence
 
+English | [中文](persistence.zh.md)
+
 The **durability seam** for the event log. [session.md](session.md) describes the in-memory `Session` — the append-only `SessionEvent` log that is the source of truth. This page describes how that log is made durable: the abstract `SessionPersistence` service, its backends, the flush checkpoint, crash recovery, and the metadata header that travels alongside the log. The event vocabulary the log carries is enumerated, member by member, in the generated [persistence log event catalog](../persistence-catalog.md).
 
 The seam is a textbook [capability seam](../../.agents/notes/implemented/architecture/2026-06-13-capability-seams.md): one abstract service ([dsh-session-persistence](../../packages/session-persistence/session-persistence), `ctx.sessionPersistence`) defining locate/create/append, crash-repairing load, non-mutating inspect, and lightweight list/snapshot observation over the existing `SessionEvent` — **no parallel persisted type** — and two interchangeable backends that pass the same `runPersistenceContract` suite. See the [session-persistence Agent Note](../../.agents/notes/implemented/architecture/2026-06-14-session-persistence.md).
@@ -53,7 +55,7 @@ interface SessionHeader {
   readonly version: number
   /** The session's id (mirrors the {@link Session}'s id). */
   readonly id: SessionId
-  /** Unix epoch milliseconds when the session was created. */
+  /** Non-negative safe-integer Unix epoch milliseconds when the session was created. */
   readonly createdAt: number
   /** Absolute working directory the session was created in (if any). */
   readonly cwd?: string