feat: conversation lifecycle status (active/idle/closed) for tab persistence

Implement roadmap item 9: tab persistence across devices.

Wire (0.10.0):
- Add ConversationStatus type (active | idle | closed)
- Add status field to ConversationMeta

Transport-contract (0.14.0):
- Add conversation.statusChanged WS message to WsServerMessage union
- Re-export ConversationStatus

Conversation-store:
- Track status in ConversationMetaRow (default: idle)
- getConversationStatus / setConversationStatus methods
- listConversations accepts { status: ConversationStatus[] } filter
- Old meta rows without status default to idle on read

Session-orchestrator:
- conversationStatusChanged hook descriptor
- Emit on transitions: idle→active (turn start), active→idle (turn settle),
  →closed (closeConversation)
- Persist status to store as fire-and-forget side effect
- Declare hook in manifest contributes.hooks

Transport-ws:
- Subscribe to conversationStatusChanged hook
- Broadcast conversation.statusChanged WS message to all clients

Transport-http:
- GET /conversations?status=active,idle filter (parseStatusFilter pure helper)
- POST /conversations/:id/close now sets status to closed

CLI:
- dispatch list defaults to active,idle (excludes closed)
- --status <state> flag to filter by single status
- --all flag to include closed

FE handoff: frontend-conversation-lifecycle-handoff.md

2 files changed, 168 insertions, 6 deletions

diff --git a/packages/conversation-store/src/store.test.ts b/packages/conversation-store/src/store.test.ts
index 1f2b7ba..fee7de5 100644
--- a/packages/conversation-store/src/store.test.ts
+++ b/packages/conversation-store/src/store.test.ts
@@ -7,6 +7,7 @@ import type {
 	TurnMetrics,
 } from "@dispatch/kernel";
 import { beforeEach, describe, expect, it } from "vitest";
+import { CONVERSATION_INDEX_KEY, metaKey } from "./keys.js";
 import { createConversationStore, extractTitle } from "./store.js";
 
 interface SpanEvent {
@@ -1023,6 +1024,7 @@ describe("ConversationStore conversation metadata + list + title", () => {
 			createdAt: 12345,
 			lastActivityAt: 12345,
 			title: "my title",
+			status: "idle",
 		});
 	});
 
@@ -1039,6 +1041,7 @@ describe("ConversationStore conversation metadata + list + title", () => {
 			createdAt: 7777,
 			lastActivityAt: 7777,
 			title: "hello",
+			status: "idle",
 		});
 	});
 
@@ -1068,6 +1071,7 @@ describe("ConversationStore conversation metadata + list + title", () => {
 			createdAt: 5000,
 			lastActivityAt: 5000,
 			title: "preset title",
+			status: "idle",
 		});
 		// And the new conversation is discoverable in the index.
 		const list = await store.listConversations();
@@ -1170,14 +1174,105 @@ describe("ConversationStore conversation metadata + list + title", () => {
 			createdAt: 1000,
 			lastActivityAt: 1000,
 			title: "persisted",
+			status: "idle",
 		});
 		const list = await store2.listConversations();
 		expect(list).toHaveLength(1);
 		expect(list[0]?.id).toBe("conv1");
 	});
-});
 
-describe("extractTitle (pure)", () => {
+	describe("ConversationStore conversation status", () => {
+		it("new conversation defaults to idle", async () => {
+			const store = createConversationStore(storage, undefined, () => 1000);
+			await store.append("conv1", [{ role: "user", chunks: [{ type: "text", text: "hi" }] }]);
+			expect(await store.getConversationStatus("conv1")).toBe("idle");
+			expect((await store.getConversationMeta("conv1"))?.status).toBe("idle");
+		});
+
+		it("setConversationStatus updates status on existing conversation", async () => {
+			const store = createConversationStore(storage, undefined, () => 1000);
+			await store.append("conv1", [{ role: "user", chunks: [{ type: "text", text: "hi" }] }]);
+
+			await store.setConversationStatus("conv1", "active");
+			expect(await store.getConversationStatus("conv1")).toBe("active");
+
+			await store.setConversationStatus("conv1", "idle");
+			expect(await store.getConversationStatus("conv1")).toBe("idle");
+
+			await store.setConversationStatus("conv1", "closed");
+			expect(await store.getConversationStatus("conv1")).toBe("closed");
+		});
+
+		it("setConversationStatus creates minimal row for unknown conversation", async () => {
+			const store = createConversationStore(storage, undefined, () => 2000);
+			await store.setConversationStatus("convNew", "closed");
+			expect(await store.getConversationStatus("convNew")).toBe("closed");
+			const meta = await store.getConversationMeta("convNew");
+			expect(meta?.status).toBe("closed");
+			expect(meta?.title).toBe("Untitled");
+		});
+
+		it("setConversationStatus preserves other metadata", async () => {
+			const store = createConversationStore(storage, undefined, () => 1000);
+			await store.append("conv1", [{ role: "user", chunks: [{ type: "text", text: "hello" }] }]);
+			await store.setConversationTitle("conv1", "custom title");
+
+			await store.setConversationStatus("conv1", "active");
+
+			const meta = await store.getConversationMeta("conv1");
+			expect(meta?.title).toBe("custom title");
+			expect(meta?.createdAt).toBe(1000);
+			expect(meta?.status).toBe("active");
+		});
+
+		it("listConversations filters by status", async () => {
+			const store = createConversationStore(storage, undefined, () => 1000);
+			await store.append("conv1", [{ role: "user", chunks: [{ type: "text", text: "a" }] }]);
+			await store.append("conv2", [{ role: "user", chunks: [{ type: "text", text: "b" }] }]);
+			await store.append("conv3", [{ role: "user", chunks: [{ type: "text", text: "c" }] }]);
+
+			await store.setConversationStatus("conv1", "active");
+			await store.setConversationStatus("conv2", "closed");
+
+			const activeOnly = await store.listConversations({ status: ["active"] });
+			expect(activeOnly.map((m) => m.id)).toEqual(["conv1"]);
+
+			const idleOnly = await store.listConversations({ status: ["idle"] });
+			expect(idleOnly.map((m) => m.id)).toEqual(["conv3"]);
+
+			const activeIdle = await store.listConversations({ status: ["active", "idle"] });
+			expect(activeIdle.map((m) => m.id)).toEqual(["conv1", "conv3"]);
+
+			const all = await store.listConversations();
+			expect(all.map((m) => m.id)).toEqual(["conv1", "conv2", "conv3"]);
+		});
+
+		it("status persists across a fresh store instance", async () => {
+			const store1 = createConversationStore(storage, undefined, () => 1000);
+			await store1.append("conv1", [{ role: "user", chunks: [{ type: "text", text: "hi" }] }]);
+			await store1.setConversationStatus("conv1", "active");
+
+			const store2 = createConversationStore(storage);
+			expect(await store2.getConversationStatus("conv1")).toBe("active");
+		});
+
+		it("old meta rows without status default to idle on read", async () => {
+			// Simulate a pre-status meta row written by an older version.
+			await storage.set(
+				metaKey("conv1"),
+				JSON.stringify({
+					createdAt: 1000,
+					lastActivityAt: 1000,
+					title: "old",
+				}),
+			);
+			await storage.set(CONVERSATION_INDEX_KEY, JSON.stringify(["conv1"]));
+
+			const store = createConversationStore(storage);
+			const meta = await store.getConversationMeta("conv1");
+			expect(meta?.status).toBe("idle");
+		});
+	});
 	it("extractTitle: returns first user text", () => {
 		const messages: ChatMessage[] = [
 			{ role: "system", chunks: [{ type: "text", text: "sys" }] },
diff --git a/packages/conversation-store/src/store.ts b/packages/conversation-store/src/store.ts
index f3bec4b..8d78df8 100644
--- a/packages/conversation-store/src/store.ts
+++ b/packages/conversation-store/src/store.ts
@@ -2,6 +2,7 @@ import type {
 	ChatMessage,
 	Chunk,
 	ConversationMeta,
+	ConversationStatus,
 	Logger,
 	ReasoningEffort,
 	Role,
@@ -71,11 +72,20 @@ export interface ConversationStore {
 	 * recent first). Metadata (createdAt, lastActivityAt, title) is tracked
 	 * automatically on append; title defaults to the first user message.
 	 */
-	readonly listConversations: () => Promise<readonly ConversationMeta[]>;
+	readonly listConversations: (filter?: {
+		readonly status?: readonly ConversationStatus[];
+	}) => Promise<readonly ConversationMeta[]>;
 	/** Single conversation metadata, or null if unknown. */
 	readonly getConversationMeta: (conversationId: string) => Promise<ConversationMeta | null>;
 	/** Set/update the human-readable title for a conversation. */
 	readonly setConversationTitle: (conversationId: string, title: string) => Promise<void>;
+	/** Get the lifecycle status of a conversation, or null if unknown. */
+	readonly getConversationStatus: (conversationId: string) => Promise<ConversationStatus | null>;
+	/** Set the lifecycle status of a conversation. Creates a minimal metadata row if missing. */
+	readonly setConversationStatus: (
+		conversationId: string,
+		status: ConversationStatus,
+	) => Promise<void>;
 }
 
 export const conversationStoreHandle = defineService<ConversationStore>("conversation-store/store");
@@ -120,6 +130,7 @@ interface ConversationMetaRow {
 	readonly createdAt: number;
 	readonly lastActivityAt: number;
 	readonly title: string;
+	readonly status: ConversationStatus;
 }
 
 /** Maximum title length (in characters) before truncation with an ellipsis. */
@@ -166,7 +177,10 @@ function parseMetaRow(raw: string): ConversationMetaRow | null {
 	) {
 		return null;
 	}
-	return parsed as ConversationMetaRow;
+	const row = parsed as ConversationMetaRow;
+	const status: ConversationStatus =
+		row.status === "active" || row.status === "closed" ? row.status : "idle";
+	return { createdAt: row.createdAt, lastActivityAt: row.lastActivityAt, title: row.title, status };
 }
 
 function toMeta(id: string, row: ConversationMetaRow): ConversationMeta {
@@ -175,6 +189,7 @@ function toMeta(id: string, row: ConversationMetaRow): ConversationMeta {
 		createdAt: row.createdAt,
 		lastActivityAt: row.lastActivityAt,
 		title: row.title,
+		status: row.status,
 	};
 }
 
@@ -241,6 +256,7 @@ export function createConversationStore(
 					createdAt: ts,
 					lastActivityAt: ts,
 					title: extractTitle(messages),
+					status: "idle",
 				};
 				await storage.set(metaKey(conversationId), JSON.stringify(row));
 				await ensureInIndex(conversationId);
@@ -252,6 +268,7 @@ export function createConversationStore(
 						createdAt: ts,
 						lastActivityAt: ts,
 						title: extractTitle(messages),
+						status: "idle",
 					};
 					await storage.set(metaKey(conversationId), JSON.stringify(row));
 					await ensureInIndex(conversationId);
@@ -264,6 +281,7 @@ export function createConversationStore(
 						createdAt: existing.createdAt,
 						lastActivityAt: ts,
 						title,
+						status: existing.status,
 					};
 					await storage.set(metaKey(conversationId), JSON.stringify(row));
 				}
@@ -387,7 +405,7 @@ export function createConversationStore(
 				logger.debug("reasoning-effort set", { conversationId });
 			}
 		},
-		async listConversations() {
+		async listConversations(filter) {
 			const raw = await storage.get(CONVERSATION_INDEX_KEY);
 			if (raw === null) return [];
 			let parsed: unknown;
@@ -407,12 +425,14 @@ export function createConversationStore(
 				ids.push(v);
 			}
 
+			const statusFilter = filter?.status;
 			const metas: ConversationMeta[] = [];
 			for (const id of ids) {
 				const metaRaw = await storage.get(metaKey(id));
 				if (metaRaw === null) continue;
 				const row = parseMetaRow(metaRaw);
 				if (row === null) continue;
+				if (statusFilter !== undefined && !statusFilter.includes(row.status)) continue;
 				metas.push(toMeta(id, row));
 			}
 			// Sort by lastActivityAt descending (most recent first). Stable sort
@@ -437,6 +457,7 @@ export function createConversationStore(
 					createdAt: ts,
 					lastActivityAt: ts,
 					title,
+					status: "idle",
 				};
 				await storage.set(metaKey(conversationId), JSON.stringify(row));
 				await ensureInIndex(conversationId);
@@ -449,16 +470,62 @@ export function createConversationStore(
 					createdAt: ts,
 					lastActivityAt: ts,
 					title,
+					status: "idle",
 				};
 				await storage.set(metaKey(conversationId), JSON.stringify(row));
 				await ensureInIndex(conversationId);
 				return;
 			}
-			// Preserve createdAt + lastActivityAt; update only the title.
+			// Preserve createdAt + lastActivityAt + status; update only the title.
 			const row: ConversationMetaRow = {
 				createdAt: existing.createdAt,
 				lastActivityAt: existing.lastActivityAt,
 				title,
+				status: existing.status,
+			};
+			await storage.set(metaKey(conversationId), JSON.stringify(row));
+		},
+
+		async getConversationStatus(conversationId) {
+			const raw = await storage.get(metaKey(conversationId));
+			if (raw === null) return null;
+			const row = parseMetaRow(raw);
+			if (row === null) return null;
+			return row.status;
+		},
+
+		async setConversationStatus(conversationId, status) {
+			const ts = now();
+			const raw = await storage.get(metaKey(conversationId));
+			if (raw === null) {
+				// Status set before any message was appended — create a minimal row.
+				const row: ConversationMetaRow = {
+					createdAt: ts,
+					lastActivityAt: ts,
+					title: "Untitled",
+					status,
+				};
+				await storage.set(metaKey(conversationId), JSON.stringify(row));
+				await ensureInIndex(conversationId);
+				return;
+			}
+			const existing = parseMetaRow(raw);
+			if (existing === null) {
+				const row: ConversationMetaRow = {
+					createdAt: ts,
+					lastActivityAt: ts,
+					title: "Untitled",
+					status,
+				};
+				await storage.set(metaKey(conversationId), JSON.stringify(row));
+				await ensureInIndex(conversationId);
+				return;
+			}
+			const row: ConversationMetaRow = {
+				createdAt: existing.createdAt,
+				lastActivityAt: existing.lastActivityAt,
+				title: existing.title,
+				status,
 			};
 			await storage.set(metaKey(conversationId), JSON.stringify(row));
 		},