fix(web): deduplicate subagent navigation

packages/client/ui-subagent/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/client/ui-subagent/README.md
-README.md: 06cfc368577a41b405336025e75e61998b2051ae
-README.zh.md: 64b096ad4804694a9b0d7d3c8c26a8f3f867bf23
+README.md: c69211bd6f84b6e09760ff47d5a319b1ef2ce28c
+README.zh.md: 43776fbc32a5bd369e837779787cdc82ceb0f749

packages/client/ui-subagent/README.md

@@ -8,6 +8,8 @@ The header action reads `subagentsByParent` and session summaries through the st
 
 An addressed child with no exact live parent elects the read-only composer entry and explains the recovery path. A child with a live parent keeps the ordinary input chrome, whose Session routes through `subagent.prompt`; this package never receives host context or calls a model-facing tool. The catalog and composer behavior are specified by the [Web subagent conversations Agent Note](../../../.agents/notes/implemented/feature/2026-07-27-web-subagent-conversations.md).
 
+Subagent-origin Session rows are omitted from the ordinary sidebar, so the parent header catalog is their navigation entry point. Ordinary forks remain in the sidebar.
+
 The `@` source remains deliberately separate and inert. Candidates are zero-RPC running children from `ctx.sessions.list`; picking one inserts literal `@label ` text, and the codec projects `@label`. It has no command-adjudication hooks and does not resolve labels into continuation addresses.
 
 ## Model Experience
@@ -29,5 +31,4 @@ Append-only. This package never edits earlier request tokens.
 ## Known Limitations and Deferred Work
 
 - **The catalog has coarse liveness only** — it cannot show durable outcome, elapsed time, exact Activation state, or a correct cancel button.
-- **The sidebar still contains child sessions** — complete de-duplication needs a scalable durable classifier that does not hide ordinary forks.
 - **`@` references remain display-title text** — duplicate or renamed labels are ambiguous, so they intentionally do not acquire continuation semantics.

packages/client/ui-subagent/README.zh.md

@@ -8,6 +8,8 @@ Web subagent 功能 owner：向 `conversation.session.header.actions` 贡献可
 
 已寻址 child 没有确切的存活 parent 时，会选中只读编辑器配置项并说明恢复路径。parent 存活时，child 保留普通输入 chrome，其 Session 会通过 `subagent.prompt` 路由；本包绝不接收宿主 context，也不调用面向模型的工具。目录与编辑器行为由 [Web subagent 对话 Agent Note](../../../.agents/notes/implemented/feature/2026-07-27-web-subagent-conversations.md)规定。
 
+普通侧边栏会省略带 subagent origin 的 Session 行，因此 parent 页头目录是它们的导航入口。普通 fork 仍保留在侧边栏中。
+
 `@` source 仍然刻意保持独立且惰性。候选是从 `ctx.sessions.list` 零 RPC 得到的运行中 child；pick 会插入字面文本 `@label `，codec 投影为 `@label`。它不参与命令裁决，也不会把 label 解析成继续执行地址。
 
 ## 模型体验
@@ -29,5 +31,4 @@ Web subagent 功能 owner：向 `conversation.session.header.actions` 贡献可
 ## 已知限制与暂缓事项
 
 - **目录只有粗粒度存活状态**：它不能显示持久化结果、耗时、确切的 Activation 状态或正确的取消按钮。
-- **侧边栏仍包含 child Session**：完全去重需要可扩展的持久化分类器，且不得误隐藏普通 fork。
 - **`@` 引用仍是显示标题文本**：重复或改名后的 label 会有歧义，因此它们刻意不获得继续执行语义。