Merge remote-tracking branch 'upstream/master' into feat/web-inline-file-mentions

# Conflicts:
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-primitives/README.i18n.yaml

packages/client/ui-conversation/README.md

@@ -8,13 +8,15 @@ Compaction renders as one collapsed row at the checkpoint's flow position withou
 
 The resident conversation shell survives no-session and session transitions. Without a current session it renders a disabled input bar; its root-scoped `conversation.hero.workspace` slot hosts the Workspace picker. Selecting a Workspace connects or reuses its Host-owned blank session and opens that session without replacing the shell. The root always owns the same scrollport and Hero/composer subtree; separate strict-session header and body outlets fill their regions when the first Session arrives, so the Workspace picker, scroll body, composer seat, and textarea retain their React and DOM identity. Blank sessions render the same composer body as active sessions, while the InputHub carries drafts across Workspace switches and mirrors them into the session store. In the active phase the session header shows only the current session title and view tabs as ordinary column chrome; fork lineage remains session data and is not projected into the header. Beneath it the scrollport (`data-conversation-scroll`) holds the flowing views and the sticky composer stack (stats dock + input docks + bar). That scrollport reserves its scrollbar gutter unconditionally, and a view opting into a composer overlay leaves it a scroll container, so the input card keeps one horizontal position whether or not the transcript scrolls and whichever view tab is shown ([decision](../../../.agents/notes/implemented/bug-fix/2026-08-04-composer-tab-gutter-reservation.md)). Wheel over the textarea chains: the capped draft scrolls locally until its edge, then forwards to that host.
 
+Another plugin can make one session's composer inert through `ctx.conversation.blocks`: it sets a block carrying its own localized reason, and the bar renders the same disabled textarea with that reason as the placeholder — the no-workspace posture, reused. The push direction is the constraint, not a preference: the plugins that know a session cannot send (ui-model, when no adapter serves its route) already depend on this package, so this package cannot read them. The model seat is the one control a block leaves live — every block this contract has is cleared by choosing a model, so locking it too would leave the composer asking for the only thing it prevents. A block is an affordance only; the Host refuses a prompt it cannot route regardless of what any client disables. The no-workspace state wins when both hold, because picking a workspace is the earlier prerequisite.
+
 The view ring is a slot: the strict session-body registration declares the session-scoped `'conversation.view'` list in its `children` table, that body renders the active entry through its renderSlot share (`only: <active id>`), and view tabs project from registration options (`id`/`order`/`label`). The chat view is this package's own entry; plugins such as ui-trajectory contribute tabs through `ctx.slots.register`, and each view owns its chrome.
 
 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 runtime manager projects every approval or question wait through `SessionSummary.pendingInteraction`, including sessions never instantiated; `ui-workspace` owns its sidebar presentation. 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 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 disclosure whose header names the role the runtime projected for the message — `上下文注入` for an injection, `跨会话召回` for a recalled session — followed by the producer name that projection read out of the durable source, so a reader distinguishes a skill catalog from a workspace instruction file or a recalled session without expanding. A source that names no producer shows the role alone. The header shares the Tool calls 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 and synthesizes no tool state, summary, or keyed toolview dispatch ([disclosure decision](../../../.agents/notes/implemented/feature/2026-07-30-web-context-injection-disclosure.md), [provenance decision](../../../.agents/notes/implemented/feature/2026-08-04-web-context-source-and-steer-marks.md)). That body follows the form the producer declared on its durable source: `instructions` names the reconciled files above their text, `catalog` lists the entries the source recorded instead of the model-facing prose, and every other value — absent, unknown to this version, or carrying no usable fields — renders the opaque body, which shows the model-facing text with its real line breaks and the remaining provenance as fields. The opaque body is the documented default, not a leftover: a resumed, forked, or foreign log must render whether or not its producer is mounted here. A durable or pending steering bubble carries an `插话` / `Interjection` caption above it, the only thing distinguishing a mid-turn interjection from the turn-opening prompt that shares its bubble.
+Logged non-user messages render as a default-collapsed disclosure whose header names the role the runtime projected for the message — `上下文注入` for an injection, `跨会话召回` for a recalled session — followed by the producer name that projection read out of the durable source, so a reader distinguishes a skill catalog from a workspace instruction file or a recalled session without expanding. A source that names no producer shows the role alone. The header shares the Tool calls 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 and synthesizes no tool state, summary, or keyed toolview dispatch ([historical disclosure decision](../../../.agents/notes/archived/feature/2026-07-30-web-context-injection-disclosure.md), [provenance decision](../../../.agents/notes/implemented/feature/2026-08-04-web-context-source-and-steer-marks.md)). That body follows the form the producer declared on its durable source: `instructions` names the reconciled files above their text, `catalog` lists the entries the source recorded instead of the model-facing prose, and every other value — absent, unknown to this version, or carrying no usable fields — renders the opaque body, which shows the model-facing text with its real line breaks and the remaining provenance as fields. The opaque body is the documented default, not a leftover: a resumed, forked, or foreign log must render whether or not its producer is mounted here. A durable or pending steering bubble carries an `插话` / `Interjection` caption above it, the only thing distinguishing a mid-turn interjection from the turn-opening prompt that shares its bubble.
 
 A Think row stays collapsed by default and exposes live reasoning throughput without expanding the chain of thought: while its reasoning block is the streaming tail, the summary switches from the settled first line to the latest non-blank line and its one-line scrollport follows each delta to the inline end. Expanding the row removes the moving summary and leaves the full reasoning in ordinary page flow, so page reading never fights an internal follower; settlement restores the stable first-line summary at the left edge ([decision](../../../.agents/notes/implemented/feature/2026-08-02-web-thinking-tail-scroll.md)).