docs: anchor each subsystem page to its package group; make group READMEs thin tables

core.md read as a type grab-bag: LLM wire vocabulary up front, the agent/loop story buried, and no correspondence to packages/core. It now opens on the packages/core control spine — the package-by-package loop map with a Page column into session/system-prompt/tools/scope — and keeps only what the spine group declares plus the repo-wide patterns: the Agent handle with its delivery/cancellation/interception contracts, the SessionEvent envelope, branded ids, the …Map pattern. The conversation vocabulary (Message/ContentBlock, the model request, adapters — 17 type-equiv blocks) moves to llm-streaming.md, which now declares packages/llm end-to-end; the duplicate ContentBlockMap paste near its seam section folds into the moved section, and the manifest, LINK_MAP, README table rows, website label (Core data structures → Core), and inbound anchors follow.

Every packages/<group>/README pair is now a thin front door in one shape: a why-first intro (bash's seam-pattern-first paragraph rewritten as 'shell execution for the agent'), the package table, and a closing pointer to the owning docs/subsystems page — the bash-style table stays the load-bearing middle. Load-bearing trailing paragraphs relocate rather than vanish: the fs no-timeout rationale becomes a filesystem.md section (both languages), session's four sectioned tables merge into one 12-row table, examples' legacy-bin H2 collapses to a pointer at jsonrpc-demo's README, and design rationale that already lives in an Agent Note or subsystem page is now linked instead of restated. All 40 pair records re-recorded.

packages/subprocess/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/subprocess/README.md
-README.md: f2b19436da40feb14d067e2cfc706222625680b5
-README.zh.md: 938312448dd5c0a691ed07ddc9843cf2c4445637
+README.md: 9a8628e2b6d16852895be33ae516c8b33b078502
+README.zh.md: d2c539fb1c66a914aa5f758d928fba01b5600d15

packages/subprocess/README.md

@@ -10,3 +10,5 @@ The shared process substrate for one execution world: executable lookup, fully-s
 | [`subprocess-local`](subprocess-local/README.md) (`@deepseek-ai/dsh-subprocess-local`) | — | The local implementation: detached process trees, bounded collection/spill, `node-pty`, foreground/session inspection, tree signalling, and terminate-and-join disposal |
 
 The service owns process lifetime across consumer reloads; consumers own what a process means (a bash command, a future non-shell runner) and every default that shapes one.
+
+The subsystem reference — spawn specs, output readers, outcomes, the `DSH_*` environment — is [docs/subsystems/subprocess.md](../../docs/subsystems/subprocess.md); the seam decision in the [subprocess seam Agent Note](../../.agents/notes/implemented/architecture/2026-07-26-subprocess-seam.md).

packages/subprocess/README.zh.md

@@ -10,3 +10,5 @@
 | [`subprocess-local`](subprocess-local/README.md)（`@deepseek-ai/dsh-subprocess-local`） | 无 | 本地实现：detached 进程树、有界收集／spill、`node-pty`、前台／会话检查、进程树信号发送，以及先终止再等待退出的资源释放 |
 
 即使消费方重载，进程生命周期仍由服务负责管理；消费方负责定义进程的含义（一条 bash 命令、未来的非 shell 运行器），以及决定塑造该进程的每一项默认值。
+
+子系统参考——spawn spec、输出读取器、结果、`DSH_*` 环境——见 [docs/subsystems/subprocess.md](../../docs/subsystems/subprocess.md)；seam 决定见 [subprocess seam Agent Note](../../.agents/notes/implemented/architecture/2026-07-26-subprocess-seam.md)。