feat(web): rewrite subagent conversations for FIFO activation

packages/client/ui-conversation/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-conversation/README.md
-README.md: fef922ab42e71813faaa826cc2580bdec72baa74
-README.zh.md: 4c1e7670bbfceaed73328108d3b5a3e646ee86bf
+README.md: 65e4542e622713e2cd120906926fc0601ef280bd
+README.zh.md: 4828ad214bb5ec0a9921307dd01dcc282910b330

packages/client/ui-conversation/README.md

@@ -12,7 +12,7 @@ The view ring IS a slot: the conversation registration declares the `'conversati
 
 Approvals take over the composer through the chain this package declares: `ApprovalPanel` registers as a selector-routed `'conversation.composer'` entry (the ui-question pattern) and occupies the composer in place of the InputBar while an approval wait is pending (amber strip, justification headline, paired command line from the running call's args, one-shot refuse/allow). The `PendingApproval` domain face in `contract/slots.ts` owns the wire encoding — the `ApprovalResponsePayload` value with the audit correlation — over the runtime's `PendingWait` carrier; the broadcast `approval/resolved` frame settles the wait and restores the composer. The sidebar mirrors the blocked state through the manager-tracked `waitingApproval` list bit (lit for uninstantiated sessions too), which outranks the running ring until the question resolves. Pending waits leave the message flow entirely: questions (ui-question) and approvals (ApprovalPanel) both answer through the composer takeover, so no display-only placeholder card remains. The composer's bottom-row Access seat mounts `PermissionSelect`, fed by the host-computed `permissions` projection through the standard-kit `useProjection` (key absence hides the chip); the chip opens a Menu-primitive dropdown whose kebab-case preset names render as title-case labels. Safe preset picks submit `/permission <preset>` immediately through the bar's injected `command` callback, while `danger-full-access` is presented as `Full access` and first opens an in-page Modal risk confirmation. The enabling action stays disabled until the user checks the acknowledgement; cancel, Escape, close, and mask click submit nothing.
 
-The session header declares and renders the session-scoped `'conversation.session.header.actions'` list beside the title, allowing feature plugins to contribute controls without entering the skeleton. The composer chain currency includes `subagentReadOnly`; ui-subagent claims that state to explain the unavailable-parent condition, while the ordinary InputBar hides Stop for every addressed continuable subagent conversation because the continuation service exposes no public per-Activation cancellation operation and `session.cancel` would bypass its ownership.
+The session header declares and renders the session-scoped `'conversation.session.header.actions'` list beside the title, allowing feature plugins to contribute controls without entering the skeleton. The composer chain currency includes the current conversation `session`; ui-subagent selects one-shot or parent-unavailable addressed sessions for reason-specific read-only copy, while the ordinary InputBar keeps every addressed child Send-only because the continuation service exposes no public per-Activation cancellation operation and `session.cancel` would bypass its ownership.
 
 Logged non-user messages render as a default-collapsed `上下文注入` disclosure. It shares the Tool calls header geometry and interaction with `ToolRow` through the package-internal `DisclosureRow`, while retaining context semantics: the expanded body follows its content height up to a 141px scrolling cap, shows inline JSON for both `content` and `source`, and synthesizes no tool state, summary, or keyed toolview dispatch ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-context-injection-disclosure.md)).
 

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

@@ -10,7 +10,7 @@
 
 视图环本身就是 slot：会话注册声明 `'conversation.view'` 列表 slot（Session scope），并将其列在 `children` 表中；ConversationRoot 通过 renderSlot share 渲染活跃配置项（`only: <active id>`）；视图标签页从环账本的注册选项（`id`／`order`／`label`）投影而来。聊天视图是该包（package）自身的环配置项；其他插件（ui-trajectory）通过普通的 `ctx.slots.register` 贡献标签页。先前包内的视图注册表（`registerView`／`ViewEntry`／`ConversationViewMap` 及 chrome 附加表）已退役，逐视图 chrome 则被拆入视图组件自身。
 
-会话页头会在标题旁声明并渲染 Session scope 的 `'conversation.session.header.actions'` 列表，使功能插件无需进入骨架即可贡献控件。编辑器链的 currency 包含 `subagentReadOnly`；ui-subagent 会接管该状态并说明 parent 不可用，而普通 InputBar 会在所有已寻址的可继续 subagent 对话中隐藏 Stop，因为继续执行服务不公开逐 Activation 取消操作，`session.cancel` 也会绕过其所有权。
+会话页头会在标题旁声明并渲染 Session scope 的 `'conversation.session.header.actions'` 列表，使功能插件无需进入骨架即可贡献控件。编辑器链的 currency 包含当前对话 `session`；ui-subagent 会选取 one-shot 或 parent 不可用的已寻址会话，并按原因显示只读文案，而普通 InputBar 会让所有已寻址 child 仅保留 Send，因为继续执行服务不公开逐 Activation 取消操作，`session.cancel` 也会绕过其所有权。
 
 已记录的非用户消息渲染为默认折叠的 `上下文注入` 展开项。它通过包内部的 `DisclosureRow` 与 `ToolRow` 共享 Tool calls 标题栏的几何与交互，同时保留上下文语义：展开内容区的高度会随内容自适应，最大为 141px，超出后滚动，并以内联 JSON 展示 `content` 和 `source`，且不会合成工具状态、摘要或键控 toolview 分发（[决策](../../../.agents/notes/implemented/feature/2026-07-30-web-context-injection-disclosure.md)）。
 

packages/client/ui-conversation/src/client/contract/slots.ts

@@ -334,8 +334,8 @@ export type ComposerBarProps =
  */
 export interface ComposerChainProps {
   interactions: readonly PendingInteraction[]
-  /** A catalog-addressed child whose exact parent Agent is unavailable. */
-  subagentReadOnly: boolean
+  /** Current conversation facts for feature-owned takeover selectors. */
+  session: ConversationSnapshot | undefined
 }
 
 /**

packages/client/ui-conversation/src/client/skeleton/ConversationRoot.tsx

@@ -19,7 +19,6 @@ export function ConversationRoot({
   const openState = useSession(s => s.openState)
   const composerPhase = useSession(s => s.composerPhase)
   const pending = useSession(s => s.pending) ?? []
-  const subagentReadOnly = useSession(s => s?.subagent?.parentAvailable === false) ?? false
   const session = useSession(s => s)
   const inputState = useInput(s => s)
   const cwd = useSessions(s => sessionId === undefined ? undefined : s.byId[sessionId]?.cwd)
@@ -154,7 +153,7 @@ export function ConversationRoot({
   const phase = settling ? 'settling' : hero ? 'hero' : 'active'
   const composer = renderSlotChain(
     'conversation.composer',
-    { interactions: pending, subagentReadOnly },
+    { interactions: pending, session },
     { fallback: composerBar, overlay: true },
   )
 

packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx

@@ -248,6 +248,8 @@ describe('bash sample row', () => {
       },
       current: undefined,
       phase: 'ready',
+      subagentsByParent: {},
+      currentAddress: undefined,
     })
   }
 

packages/client/ui-conversation/tests/coverage-tails.spec.tsx

@@ -96,6 +96,8 @@ describe('tails', () => {
       byId: { [sid]: { id: sid, title: 'r', displayTitle: 'r', running: false, waitingApproval: false, blank: false, updatedAt: 0 } },
       current: undefined,
       phase: 'ready',
+      subagentsByParent: {},
+      currentAddress: undefined,
     })
     const props = (block: RunningToolCall | ToolResultNode) => ({
       callId: 'c1', toolName: 'bash', block, openFile: vi.fn(),