docs: rename core-data-structures/ to subsystems/

The folder is becoming the home of one-doc-per-subsystem pages (intro +
data structures + cordis services/events), so the name must describe the
whole contract, not just the type-vocabulary third of it. Mechanical
rename rebuilt on current master: every inbound Markdown link, generator
constant, website route, type-equiv manifest path, and spec expectation
moves together; the zh sides of the notes whose prose names the folder
are aligned (子系统) in the same change; touched bilingual pairs
re-recorded; translation-prompt snapshot re-recorded (its example embeds
development.md). Historical Agent Note slugs keep their dated
filenames.

packages/core/session/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/core/session/README.md
-README.md: e2c014a1448125b23475d6cdf52c02f10fc54794
-README.zh.md: a4aeead796961bd66a6c7ca1f9a66dffb60eba5d
+README.md: 07ee53006b390e5ad3979502b2f1aa24f5a6ce7a
+README.zh.md: d4a90de10b92a489f8f575b926d758b45d8f5051

packages/core/session/README.md

@@ -56,7 +56,7 @@ The shared [storage codec](src/chunk-rows.ts) losslessly converts event sequence
 
 ### Surface types
 
-This package owns ordered surface projection, replacement validation, replay, and the type guards that distinguish append-origin from replacement events. The [surface type catalog](../../../docs/core-data-structures/session.md#surface-types) owns the exact shapes and field semantics. A human transcript must project append-origin events rather than `session.surface`, because landed replacements shadow history the reader already saw; model-facing consumers continue to read `session.surface`.
+This package owns ordered surface projection, replacement validation, replay, and the type guards that distinguish append-origin from replacement events. The [surface type catalog](../../../docs/subsystems/session.md#surface-types) owns the exact shapes and field semantics. A human transcript must project append-origin events rather than `session.surface`, because landed replacements shadow history the reader already saw; model-facing consumers continue to read `session.surface`.
 
 ### Request-header reconstruction (`request-header.ts`)
 

packages/core/session/README.zh.md

@@ -56,7 +56,7 @@
 
 ### Surface 类型
 
-此包拥有有序 surface 投影、替换校验、回放，以及区分追加来源事件与替换事件的类型守卫。[surface 类型目录](../../../docs/core-data-structures/session.md#surface-types)拥有精确形状与字段语义。面向人的 transcript（文本记录）必须投影追加来源事件，而不是 `session.surface`，因为已落地的替换会遮蔽读者已经看到的历史；面向模型的消费方继续读取 `session.surface`。
+此包拥有有序 surface 投影、替换校验、回放，以及区分追加来源事件与替换事件的类型守卫。[surface 类型目录](../../../docs/subsystems/session.md#surface-types)拥有精确形状与字段语义。面向人的 transcript（文本记录）必须投影追加来源事件，而不是 `session.surface`，因为已落地的替换会遮蔽读者已经看到的历史；面向模型的消费方继续读取 `session.surface`。
 
 ### 请求头重建（`request-header.ts`）
 

packages/core/tools/src/index.ts

@@ -39,7 +39,7 @@ import { renderToolsSdkPy } from './py-types.ts'
  * the flavor table is checked against too, so any of the three left out is a
  * typecheck failure. What no check reaches is the prose that names the values
  * instead of deriving them: the seam's `dsh-code-runtime` README pair, its
- * `CodeRuntime.language` JSDoc, and `docs/core-data-structures/code-runtime.md`
+ * `CodeRuntime.language` JSDoc, and `docs/subsystems/code-runtime.md`
  * with its zh pair, plus this package's own README pair and the
  * {@link Config.mode} JSDoc.
  */