docs(i18n): core-data-structures and postmortem batch — 22 bilingual pairs

core-data-structures 18 篇（core.md 因超长仍在产出、随后补）、
postmortem 3 篇与 RFC 前门 README 配对；流水线 + 二遍校验产出。
生成文件 docs/rfc/INDEX.md（gen-rfc-index 产物）列入排除。中文侧
页内锚点统一指向英文侧锚名，满足配对门禁的链接目标一致规则。

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](../rfc/implemented/architecture/2026-06-13-capability-seams.md): one abstract service ([dsh-session-persistence](../../packages/session-persistence/session-persistence), `ctx.sessionPersistence`) defining create/append/load/list over the existing `SessionEvent` — **no parallel persisted type** — and two interchangeable backends that pass the same `runPersistenceContract` suite. See the [session-persistence RFC](../rfc/implemented/architecture/2026-06-14-session-persistence.md).