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/approval.md

@@ -1,5 +1,7 @@
 # User Approval
 
+English | [中文](approval.zh.md)
+
 The user-approval seam of [dsh-user-approval](../../packages/ui/user-approval) answers one question: may this specific action proceed? It owns the shared request/outcome vocabulary, the `ctx.approval` dispatch service, the `approval/request` answerer waterfall, the log-only audit pair, and the per-session `ask`/`never` policy. UI channels such as [dsh-acp](../../packages/ui/acp) provide answerers; callers such as [dsh-tools](../../packages/core/tools) and [dsh-tool-bash](../../packages/bash/tool-bash) consume the closed outcome and fail closed unless it is `allowed-once`.
 
 Source: [`packages/ui/user-approval/src/index.ts`](../../packages/ui/user-approval/src/index.ts)