docs(web): the composer bar is one session-maybe slot, not a swapped pair

fix(web): keep one composer bar DOM across the no-workspace transition

The composer.bar slot moves from session to session-maybe scope: with no
current session the entry still mounts, the machine faces (keyboard, stop,
command) arrive undefined, and the bar renders its normal DOM inert via the
disabled owner prop. DisabledInputBar and its parallel tree are gone, so the
textarea node survives the cold-start workspace pick instead of flashing
through a remount. A blank session whose workspace was deleted takes the
same inert path through owner props.

test(web): add the composer DOM-continuity acceptance probe

Drives a real dsh web server with headless chromium through the cold-start
-> pick-workspace -> type flow and asserts the composer textarea is the
same DOM node throughout (a marker property must survive). Rerun
prerequisites are in the header comment.

docs(web): session-maybe identity is adoption, not hold-forever

fix(web): session-maybe entries adopt the first session, then remount like strict entries

A session-maybe entry used to keep one React instance across every
transition, so component-local state leaked between sessions once the
composer bar moved to that scope (PermissionSelect's optimistic pick, the
IME composition guard). Identity is now adoption: an incarnation born
session-less holds through the arrival of the first session (the blank
shell's DOM survives the workspace pick), and afterwards behaves exactly
like a strict session entry — a switch or a drop to no-session remounts,
clearing local state by construction. The child key is an incarnation
counter kept in the stable outlet wrapper via render-phase setState.

chore: knip knows the root acceptance probe's playwright dependency

scripts/hero-composer-dom-continuity.mjs resolves playwright through
apps/web's devDependency tree (createRequire), which knip cannot follow;
ignore it at the root workspace.

.agents/notes/implemented/architecture/2026-07-25-web-client-session-scope-and-provide-channel.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/2026-07-25-web-client-session-scope-and-provide-channel.md
-2026-07-25-web-client-session-scope-and-provide-channel.md: 4496e3786ed4adb6e60dfd5cfad72e989657f649
-2026-07-25-web-client-session-scope-and-provide-channel.zh.md: 768dada95aacdb358115d496f45e7fc0eece0151
+2026-07-25-web-client-session-scope-and-provide-channel.md: d19b256b834110d3cbb540cc0e039e61c693e98c
+2026-07-25-web-client-session-scope-and-provide-channel.zh.md: 1f88dd2065eaba7282ae3ed9e82d6872fdfb8497

.agents/notes/implemented/architecture/2026-07-25-web-client-session-scope-and-provide-channel.md

@@ -90,10 +90,10 @@ The sole provisioning path by which session slot components fetch their own sess
 Slot scope is the closed set `root | session-maybe | session`:
 
 - `root` receives only the global standard kit, with no session identity or provisioning.
-- `session-maybe` follows the current session, but the component instance does not change key when the id appears, disappears, or changes; with no session, `sessionId`, the results of `useSession`/`useInput`, and `inputActions` may all be absent. The unkeyed root `SessionMaybeProvider` drives these updates by subscribing to the runtime's atomic `currentProvide` projection — selection moves and provider-roster changes publish through the same source, so a roster change under a stable current id republishes the mounted bundle instead of stranding entries on an obsolete hook/prop schema — while `SessionMaybeProvideInfo` uses the static key map to retain the complete hook/prop shape even with no session.
+- `session-maybe` follows the current session with ADOPTION identity (the only behavior — there is no hold-identity-forever mode): an incarnation born session-less keeps its React instance across the arrival of the FIRST session (the blank shell adopts it — no remount, the DOM survives), and from then on behaves exactly like a strict session entry — switching to a different session remounts, and dropping back to no-session remounts into a fresh blank incarnation that will adopt again. Component-local per-session state therefore clears by construction; state that must survive a switch belongs in session-bound sources (machine, store, hooks). With no session, `sessionId`, the results of `useSession`/`useInput`, and `inputActions` may all be absent. The unkeyed root `SessionMaybeProvider` drives these updates by subscribing to the runtime's atomic `currentProvide` projection — selection moves and provider-roster changes publish through the same source, so a roster change under a stable current id republishes the mounted bundle instead of stranding entries on an obsolete hook/prop schema — while `SessionMaybeProvideInfo` uses the static key map to retain the complete hook/prop shape even with no session; the per-entry adoption bookkeeping (incarnation-counter key) lives in the renderer's `SessionMaybeEntry`.
 - `session` guarantees that `sessionId`, every hook source, and every prop exist; each strict entry's error boundary is keyed by `sessionId`, so switching sessions recreates that entry and its session store.
 
-`conversation` is the resident `session-maybe` shell: `ConversationRoot`, HeroShell, the Workspace picker, the composer stack, and the overlay chain's fallback frame retain their React instances across the no-session → blank-session switch; `conversation.session` carries only the strict-session header/view, while the composer and every input slot also stay strict `session`. With no session, the composer stack places the presentation-only `DisabledInputBar` directly; once a session appears, the input body is swapped for the strictly bound InputBar; the textarea may be rebuilt, while the Hero and the layout skeleton are not. The blank → engaging/active transition stays inside the same strict-session subtree, and the InputBar is never rebuilt on a phase flip.
+`conversation` is the resident `session-maybe` shell: `ConversationRoot`, HeroShell, the Workspace picker, the composer stack, and the overlay chain's fallback frame retain their React instances across the no-session → blank-session switch; `conversation.session` carries only the strict-session header/view. The composer bar (`conversation.composer.bar`) is itself `session-maybe`: with no session it renders inert (machine faces absent, `disabled` owner prop), and the same instance — textarea included — goes live when a session appears; the remaining input slots stay strict `session` and dispatch nothing until then. The blank → engaging/active transition never rebuilds the InputBar on a phase flip.
 
 - The runtime's first built-in entry: the `'session'` hook — `useSession` itself rides the same mechanism, no special-casing.
 - Concurrent discipline: the render plane reads only from the hooks compartment (uSES consistency guarantee); props-compartment callbacks are used only in event-handler space; descriptor resolution is render-safe (idempotent caching, with prune reaping residue from abandoned renders).

.agents/notes/implemented/architecture/2026-07-25-web-client-session-scope-and-provide-channel.zh.md

@@ -90,10 +90,10 @@ session slot 组件「自己拿 session 数据」的唯一供数路径。插件
 slot scope 是闭集 `root | session-maybe | session`：
 
 - `root` 只拿全局标准件，不接收 session 身份或供数。
-- `session-maybe` 跟随 current session，但组件实例不因 id 有无或切换而换 key；无 session 时 `sessionId`、`useSession`/`useInput` 的选择结果及 `inputActions` 均可缺省。根部无 key 的 `SessionMaybeProvider` 通过订阅 runtime 的原子 `currentProvide` 投影驱动这条更新——选择移动与 provider 名册变化经同一 source 发布，current id 不变时的名册变化也会重发已挂载 bundle，而不是把 entry 困在过期的 hook/prop 形状上——`SessionMaybeProvideInfo` 靠静态键表在无 session 时仍保留完整 hook/prop 形状。
+- `session-maybe` 以**收养（adoption）身份语义**跟随 current session（唯一行为——不存在「永久保持实例」模式）：空态出生的化身在**第一个** session 到来时保持 React 实例（空壳收养它——不重挂，DOM 存活）；此后行为与严格 session entry 完全一致——切到不同 session 重挂，跌回无 session 也重挂为崭新的空态化身（之后再次收养）。因此组件本地的 per-session 状态**由构造保证**随切换清零；需要活过切换的状态必须住 session 绑定的源（machine、store、hooks）。无 session 时 `sessionId`、`useSession`/`useInput` 的选择结果及 `inputActions` 均可缺省。根部无 key 的 `SessionMaybeProvider` 通过订阅 runtime 的原子 `currentProvide` 投影驱动这条更新——选择移动与 provider 名册变化经同一 source 发布，current id 不变时的名册变化也会重发已挂载 bundle，而不是把 entry 困在过期的 hook/prop 形状上——`SessionMaybeProvideInfo` 靠静态键表在无 session 时仍保留完整 hook/prop 形状；逐 entry 的收养记账（化身计数 key）住在 renderer 的 `SessionMaybeEntry`。
 - `session` 保证 `sessionId`、所有 hook source 与 props 均存在；每个严格 entry 的错误边界以 `sessionId` 为 key，切换 session 会重建该 entry 及其 session store。
 
-`conversation` 是 `session-maybe` 的常驻外壳：`ConversationRoot`、HeroShell、Workspace picker、composer stack 与 overlay chain 的 fallback 外框在无 session → blank session 的切换中保持 React 实例；`conversation.session` 只承载严格 session 的 header/view，composer 与各输入 slot 也保持严格 `session`。无 session 时 composer stack 直接放纯展示的 `DisabledInputBar`，session 出现后把输入体换成严格绑定的 InputBar；textarea 允许重建，Hero 与布局骨架不重建。blank → engaging/active 仍在同一严格 session subtree 内，InputBar 不因 phase 翻转而重建。
+`conversation` 是 `session-maybe` 的常驻外壳：`ConversationRoot`、HeroShell、Workspace picker、composer stack 与 overlay chain 的 fallback 外框在无 session → blank session 的切换中保持 React 实例；`conversation.session` 只承载严格 session 的 header/view。composer bar（`conversation.composer.bar`）本身即为 `session-maybe`：无 session 时以惰性态渲染（machine face 缺席、`disabled` owner prop），session 出现后同一实例（含 textarea）转为 live；其余输入 slot 保持严格 `session`，在此之前不分发任何条目。blank → engaging/active 的 InputBar 不因 phase 翻转而重建。
 
 - runtime 内建第一条：`'session'` hook——`useSession` 本身走同一机制，无特判。
 - Concurrent 纪律：渲染平面只从 hooks 格读（uSES 一致性保证）；props 格回调只在事件 handler 空间用；描述符解析 render-safe（幂等缓存、废弃渲染残留由 prune 收尸）。

.agents/notes/implemented/architecture/2026-07-25-web-input-machine-and-slash-pipeline.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/2026-07-25-web-input-machine-and-slash-pipeline.md
-2026-07-25-web-input-machine-and-slash-pipeline.md: f446f42c9e202afcb404c7a551a4f715228bb8e5
-2026-07-25-web-input-machine-and-slash-pipeline.zh.md: 8f5e449bb878811b70bc5bc29e4a09bbc1a33bfa
+2026-07-25-web-input-machine-and-slash-pipeline.md: 92bb91c3e892d928cedf18ec57c725a116b6ffc8
+2026-07-25-web-input-machine-and-slash-pipeline.zh.md: 5bee6df52f16d935aa4f4ccff8627a2d43d44c8c

.agents/notes/implemented/architecture/2026-07-25-web-input-machine-and-slash-pipeline.md

@@ -70,7 +70,7 @@ A trigger/menu/pick pipeline with zero knowledge of "commands":
 
 - The hub (trigger/decoration registries + send orchestration) takes the slash/command services as optional `ctx.get()` dependencies: without ui-slash or the command surfaces, input still sends and receives normally — graceful degradation.
 - Each materialized Session has exactly one `SessionInputShell` (the facade), created and torn down with the session scope; with no session, no input machine is built. `ConversationRoot` is itself the `session-maybe` resident shell, holding HeroShell, the Workspace picker, the composer stack, and the chain-fallback frame.
-- With no session the shell renders the presentation-only `DisabledInputBar`; once `connectWorkspace` returns a blank session, only the input body is swapped for the strict-session InputBar. The textarea may be rebuilt here, while `ConversationRoot`, the Hero, and the layout skeleton hold; blank → engaging/active stays the same session-bound InputBar, with the textarea never rebuilt on a phase flip.
+- The composer bar is one `session-maybe` slot entry rendered unconditionally: with no session the same InputBar renders inert (machine faces absent, `disabled` owner prop), and once `connectWorkspace` returns a blank session the same instance goes live — the textarea DOM survives the no-session → blank transition and every later phase flip; `ConversationRoot`, the Hero, and the layout skeleton hold throughout.
 - ConversationRoot's Hero criterion is `sessionId === undefined || (composerPhase === 'blank' && (openState === 'open' || openState === 'loading'))`. The first submit enters engaging synchronously, and a failure keeps the composer and the error context rather than falling back to the blank Hero; the sidebar's blank bit flips false only after a prompt is successfully accepted.
 - Sending unifies in the hub defaultSink: after an optimistic draft clear it goes only through `session.prompt {mode:'queue'|'steer'}`; backfill happens only when it fails and the live draft is still empty — a user who has kept typing is never overwritten. No Draft materialize or attach transaction exists.
 - When the blank Hero re-picks the Workspace, the shell calls `connectWorkspace`; if the target session differs, the non-empty draft moves from the current shell to the target shell before the new id is opened, and the old blank session survives but is no longer current.

.agents/notes/implemented/architecture/2026-07-25-web-input-machine-and-slash-pipeline.zh.md

@@ -70,7 +70,7 @@ occurrence 表与 chip 三投影：
 
 - hub（trigger/decoration 注册表 + 发送编排）对 slash/command 服务是可选 `ctx.get()` 依赖：无 ui-slash/命令面时输入正常收发，优雅降级。
 - 每个实体 Session 只有一个 `SessionInputShell`（facade），随 session scope 创建和拆除；无 session 时不造 input machine。`ConversationRoot` 自身是 `session-maybe` 常驻外壳，持有 HeroShell、Workspace picker、composer stack 与 chain fallback 外框。
-- 无 session 时外壳渲染纯展示的 `DisabledInputBar`；`connectWorkspace` 返回 blank session 后，仅输入体换成严格 session 的 InputBar。这里允许 textarea 重建，`ConversationRoot`、Hero 与布局骨架保持；blank → engaging/active 仍是同一 session-bound InputBar，textarea 不因 phase 翻转而重建。
+- composer bar 是一个无条件渲染的 `session-maybe` slot entry：无 session 时同一个 InputBar 以惰性态渲染（machine face 缺席、`disabled` owner prop），`connectWorkspace` 返回 blank session 后同一实例转为 live——textarea DOM 在无 session → blank 切换及其后每次 phase 翻转中都不重建；`ConversationRoot`、Hero 与布局骨架全程保持。
 - ConversationRoot 的 Hero 判据是 `sessionId === undefined || (composerPhase === 'blank' && (openState === 'open' || openState === 'loading'))`。首次 submit 同步进入 engaging，失败也保留 composer 与错误上下文，不退回 blank Hero；sidebar 的 blank 位只在 prompt 成功受理后翻 false。
 - 发送统一在 hub defaultSink：乐观清稿后只走 `session.prompt {mode:'queue'|'steer'}`；失败且 live draft 仍为空才回填，用户已经继续输入则不覆盖。不存在 Draft materialize 或 attach 事务。
 - blank Hero 改选 Workspace 时，外壳调用 `connectWorkspace`；目标 session 不同时把非空 draft 从当前 shell 搬到目标 shell，再 open 新 id，旧 blank session 留存但不再 current。