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/tasks/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/tasks/README.md
-README.md: 05ed9c439684337c45abe11f03c861a1b795b2ac
-README.zh.md: 16fe6c0a2b183b719cb6aa8ac068e34d51832a2b
+README.md: e0b6769cd1d28cc7159310a6ec6f5c8d94a81a24
+README.zh.md: d030081470a503fb52fd72dcc6f89f4c535dc38c

packages/tasks/README.md

@@ -11,3 +11,5 @@ This family gives long-running tools one owner-isolated background-task protocol
 | [`tool-tasks/`](tool-tasks/README.md) | Exposes task control and completion notices to the model | registers on `ctx.tools` |
 
 See the [background-task runtime](../../.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.md) and [task-registry](../../.agents/notes/implemented/architecture/2026-07-26-task-registry-seam.md) decisions.
+
+The subsystem reference — the id scheme, the owner-fenced contract, snapshots — is [docs/subsystems/tasks.md](../../docs/subsystems/tasks.md); design in the [background-task runtime](../../.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.md) and [task-registry seam](../../.agents/notes/implemented/architecture/2026-07-26-task-registry-seam.md) Agent Notes.

packages/tasks/README.zh.md

@@ -11,3 +11,5 @@
 | [`tool-tasks/`](tool-tasks/README.md) | 向模型公开任务控制和完成通知 | 注册到 `ctx.tools` |
 
 参见[后台任务运行时](../../.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.md)和[任务注册表](../../.agents/notes/implemented/architecture/2026-07-26-task-registry-seam.md)决策。
+
+子系统参考——id 方案、拥有者围栏契约、快照——见 [docs/subsystems/tasks.md](../../docs/subsystems/tasks.md)；设计见[后台任务运行时](../../.agents/notes/implemented/architecture/2026-06-20-generic-long-running-tool-runtime.md)与[任务注册表 seam](../../.agents/notes/implemented/architecture/2026-07-26-task-registry-seam.md) Agent Note。