docs: give subsystems/ its own README index; retire the data-structures-catalog framing

core.md doubled as the folder index: its intro claimed "this folder catalogs the data structures" and carried the 38-row page table, wording that predates the one-page-per-subsystem shape where every page also carries its generated Cordis surface. The folder index now lives in docs/subsystems/README.md (page table plus the type-equiv note), and core.md is one subsystem page among siblings: the spine vocabulary. Structural referents move with it: the docs/AGENTS.md tier table and update rule, development.md's type-equiv pointer, the dsh-code-review skill, the two owning catalog Agent Notes, and website/docs.ts (README projects as reference/subsystems/index.md and takes the docs/subsystems folder alias; sidebar orders shift by one). Remaining "data-structure catalog" / "sub-page" phrasing in active notes and READMEs is reworded to subsystem-page terms in both languages; touched pairs re-recorded; translation-prompt snapshot re-recorded (its example embeds development.md).

.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.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 .agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.md
-2026-06-20-generic-long-running-tool-runtime.md: 90100ea8f146e505c4fbb95760781839bd4bd34a
-2026-06-20-generic-long-running-tool-runtime.zh.md: bdcd8e8fe2a50033177354ce5ce043c4b5264621
+2026-06-20-generic-long-running-tool-runtime.md: 8cf6a34c3e4fc042bd73c147d83838734dfc9585
+2026-06-20-generic-long-running-tool-runtime.zh.md: 5af06b78e97980822687cdc82d9b0672a42b6fc2

.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.md

@@ -23,7 +23,7 @@ Long-running tools are producers. `dsh-tool-bash` adapts a `BashProcess` into in
 
 ## Runtime contract
 
-The literal types live in the [task data-structure catalog](../../../../docs/subsystems/tasks.md). A producer calls `ctx.tasks.start()` with a kind, label, optional owning `Agent`, optional positive `outputLimitBytes`, and a `run()` function. The runtime completes all failable preflight work before calling `run()` and invokes it once. After `run()` returns hooks, registration commits without another failable step; a producer cannot start work that lacks a collectable task id.
+The literal types live on the [tasks subsystem page](../../../../docs/subsystems/tasks.md). A producer calls `ctx.tasks.start()` with a kind, label, optional owning `Agent`, optional positive `outputLimitBytes`, and a `run()` function. The runtime completes all failable preflight work before calling `run()` and invokes it once. After `run()` returns hooks, registration commits without another failable step; a producer cannot start work that lacks a collectable task id.
 
 `outputLimitBytes` is producer-owned presentation policy, not a registry buffer. The registry validates and projects it unchanged into `TaskSnapshot`; generic control surfaces apply the cap to complete model-facing output after adding their own status or notice metadata. Omitting it preserves the existing surface behavior, so the runtime does not impose a hidden default on unrelated producer families.
 

.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.zh.md

@@ -23,7 +23,7 @@ Status: implemented
 
 ## 运行时契约
 
-字面类型见[任务数据结构目录](../../../../docs/subsystems/tasks.md)。生产方调用 `ctx.tasks.start()`，传入 kind、label、可选的所属 `Agent`、可选的正数 `outputLimitBytes` 与一个 `run()` 函数。运行时会在调用 `run()` 前完成所有可能失败的预检工作，并且只调用一次。`run()` 返回钩子后，注册过程不会再执行可能失败的步骤而直接提交；生产方无法启动没有可收集 task id 的工作。
+字面类型见[任务子系统页面](../../../../docs/subsystems/tasks.md)。生产方调用 `ctx.tasks.start()`，传入 kind、label、可选的所属 `Agent`、可选的正数 `outputLimitBytes` 与一个 `run()` 函数。运行时会在调用 `run()` 前完成所有可能失败的预检工作，并且只调用一次。`run()` 返回钩子后，注册过程不会再执行可能失败的步骤而直接提交；生产方无法启动没有可收集 task id 的工作。
 
 `outputLimitBytes` 是生产方拥有的呈现策略，而非注册表缓冲区。注册表校验该值，并将其原样投影到 `TaskSnapshot`；通用控制接口添加自身的状态或通知元数据后，再将该上限应用于完整的面向模型输出。省略该值时保持现有接口行为，因此运行时不会向无关的生产方类别施加隐式默认值。