feat(tabs): cross-device tab sync via conversation lifecycle

Consume the conversation lifecycle handoff ([email protected], [email protected]).
Re-pinned file: deps + re-mirrored .dispatch/*.reference.md.

- fetchOpenConversations() on connect: GET /conversations?status=active,idle
  restores the tab bar across devices (merges with localStorage — opens new
  tabs, removes closed ones, updates titles from backend)
- conversation.statusChanged WS handler: closed → removeTabLocally (no
  re-POST); active → open tab + spinner; idle → update status map
- conversation.compacted WS handler: dispose stale store + cache, reload
  history from server
- TabBar shows a spinner on active conversations (statusFor prop)
- closeTab refactored to use removeTabLocally (extracted cleanup)
- conformance guards + WS adapter tests cover all 3 new WsServerMessage types

686 tests green.

2 files changed, 57 insertions, 4 deletions

diff --git a/.dispatch/transport-contract.reference.md b/.dispatch/transport-contract.reference.md
index d5f22c7..e599eb3 100644
--- a/.dispatch/transport-contract.reference.md
+++ b/.dispatch/transport-contract.reference.md
@@ -5,10 +5,19 @@
 > hangs on a permission prompt). Your CODE still imports `@dispatch/transport-contract` normally —
 > this file is for READING only.
 >
-> **Orchestrator:** SNAPSHOT of `[email protected]` (conversation.open broadcast).
-> Depends on `@dispatch/[email protected]` (see `wire.reference.md`) + `@dispatch/[email protected]` (see
+> **Orchestrator:** SNAPSHOT of `[email protected]` (conversation lifecycle).
+> Depends on `@dispatch/[email protected]` (see `wire.reference.md`) + `@dispatch/[email protected]` (see
 > `ui-contract.reference.md`).
 >
+> **2026-06-22 delta (conversation lifecycle handoff — package bumped `0.13.0` → `0.14.0`, ADDITIVE):**
+> adds conversation lifecycle **status** (`active`/`idle`/`closed`) for cross-device tab
+> persistence. `ConversationMeta` (re-exported from `[email protected]`) gains a `status` field. New
+> WS message `ConversationStatusChangedMessage` (`{ type: "conversation.statusChanged";
+> conversationId; status }`) is broadcast to ALL clients on every status change. `GET
+> /conversations` gains an optional `?status=active,idle` filter (comma-separated; default = all).
+> `POST /conversations/:id/close` now also sets status to `closed` (persists across restarts).
+> The FE fetches `?status=active,idle` on connect to restore the tab bar across devices.
+>
 > **2026-06-21 delta (conversation.open handoff — package bumped `0.12.0` → `0.13.0`, ADDITIVE):**
 > adds the `conversation.open` WS broadcast — when the CLI's `--open` flag fires
 > (`POST /conversations/:id/open`), the backend broadcasts a `ConversationOpenMessage`
@@ -212,6 +221,7 @@ import type { SurfaceClientMessage, SurfaceServerMessage } from "@dispatch/ui-co
 import type {
 	AgentEvent,
 	ConversationMeta,
+	ConversationStatus,
 	QueuedMessage,
 	ReasoningEffort,
 	StoredChunk,
@@ -221,6 +231,7 @@ import type {
 export type {
 	AgentEvent,
 	ConversationMeta,
+	ConversationStatus,
 	QueuedMessage,
 	ReasoningEffort,
 	StepMetrics,
@@ -666,7 +677,9 @@ export type WsServerMessage =
 	| SurfaceServerMessage
 	| ChatDeltaMessage
 	| ChatErrorMessage
-	| ConversationOpenMessage;
+	| ConversationOpenMessage
+	| ConversationStatusChangedMessage
+	| ConversationCompactedMessage;
 
 // ─── Conversation list + metadata ────────────────────────────────────────────
 
@@ -681,6 +694,29 @@ export interface ConversationOpenMessage {
 }
 
 /**
+ * Broadcast to all connected WS clients when a conversation's lifecycle status
+ * changes (`active`/`idle`/`closed`). The FE uses this for cross-device tab
+ * sync: `closed` → remove the tab; `active` → show a generating indicator.
+ */
+export interface ConversationStatusChangedMessage {
+	readonly type: "conversation.statusChanged";
+	readonly conversationId: string;
+	readonly status: ConversationStatus;
+}
+
+/**
+ * Broadcast to all connected WS clients when a conversation's history has been
+ * compacted (summarized). The frontend should reload the conversation history
+ * via `GET /conversations/:id` to reflect the compacted state.
+ */
+export interface ConversationCompactedMessage {
+	readonly type: "conversation.compacted";
+	readonly conversationId: string;
+	readonly messagesSummarized: number;
+	readonly messagesKept: number;
+}
+
+/**
  * Response for `GET /conversations` — the list of all known conversations,
  * sorted by `lastActivityAt` descending (most recent first). Each entry carries
  * enough metadata for a conversation picker UI (id, title, timestamps).
diff --git a/.dispatch/wire.reference.md b/.dispatch/wire.reference.md
index e96c353..ead4d9c 100644
--- a/.dispatch/wire.reference.md
+++ b/.dispatch/wire.reference.md
@@ -4,9 +4,17 @@
 > types WITHOUT following the `file:` dep symlink out of this repo (which hangs on a permission
 > prompt). Your CODE still imports `@dispatch/wire` normally — this file is for READING only.
 >
-> **Orchestrator:** SNAPSHOT of `[email protected]` (conversation metadata). Regenerate
+> **Orchestrator:** SNAPSHOT of `[email protected]` (conversation lifecycle status). Regenerate
 > whenever `@dispatch/wire` changes.
 >
+> **2026-06-22 delta (conversation lifecycle handoff — package bumped `0.9.0` → `0.10.0`, ADDITIVE):**
+> adds `ConversationStatus` (`"active" | "idle" | "closed"`) — the per-conversation lifecycle
+> status. `ConversationMeta` gains a `status` field. `active` = a turn is generating; `idle` =
+> exists, not generating; `closed` = dismissed (hidden from the tab bar). Transitions are
+> backend-owned: `idle → active` on turn start, `active → idle` on turn settle, `→ closed` on
+> `POST /conversations/:id/close`. Pushed to all WS clients via `conversation.statusChanged`
+> (see `[email protected]`).
+>
 > **2026-06-21 delta (conversation.open handoff — package bumped `0.8.0` → `0.9.0`, ADDITIVE):**
 > adds `ConversationMeta` — metadata for a conversation (id, title, createdAt, lastActivityAt),
 > returned by `GET /conversations` (the list endpoint, see `[email protected]`).
@@ -585,6 +593,14 @@ export interface TurnSteeringEvent {
 // ─── Conversation metadata ───────────────────────────────────────────────────
 
 /**
+ * The per-conversation lifecycle status. `active` = a turn is generating;
+ * `idle` = exists, not generating; `closed` = dismissed (hidden from the tab
+ * bar, not deleted). Transitions are backend-owned and pushed via the
+ * `conversation.statusChanged` WS message (see `transport-contract`).
+ */
+export type ConversationStatus = "active" | "idle" | "closed";
+
+/**
  * Metadata for a conversation, returned by `GET /conversations` (the list
  * endpoint). The title defaults to the first user message (truncated) and can
  * be set via `PUT /conversations/:id/title`. `createdAt` is set on first write;
@@ -595,5 +611,6 @@ export interface ConversationMeta {
 	readonly createdAt: number;
 	readonly lastActivityAt: number;
 	readonly title: string;
+	readonly status: ConversationStatus;
 }
 ```