feat(cli): Wave 0 — contracts for conversation list, last message, open tab

Additive contract changes for the CLI milestone (roadmap items 2 + 4):

@dispatch/wire 0.8.0 → 0.9.0:
- ConversationMeta { id, createdAt, lastActivityAt, title }

@dispatch/transport-contract 0.12.0 → 0.13.0:
- ConversationListResponse, LastMessageResponse, OpenConversationResponse
- SetTitleRequest, TitleResponse
- WS conversation.open broadcast (additive to WsServerMessage)

ConversationStore interface:
- listConversations(), getConversationMeta(), setConversationTitle()
- Stub implementations in real store + 11 test fakes (Wave 1 fills in)

Transport-http manifest: new routes declared
(GET /conversations, GET /conversations/:id/last,
POST /conversations/:id/open, PUT /conversations/:id/title)

12 files changed, 182 insertions, 3 deletions

diff --git a/packages/conversation-store/src/store.ts b/packages/conversation-store/src/store.ts
index ef5654b..188f780 100644
--- a/packages/conversation-store/src/store.ts
+++ b/packages/conversation-store/src/store.ts
@@ -1,6 +1,7 @@
 import type {
 	ChatMessage,
 	Chunk,
+	ConversationMeta,
 	Logger,
 	ReasoningEffort,
 	Role,
@@ -63,6 +64,16 @@ export interface ConversationStore {
 	readonly getReasoningEffort: (conversationId: string) => Promise<ReasoningEffort | null>;
 	/** Persist (upsert) the reasoning-effort level for a conversation. */
 	readonly setReasoningEffort: (conversationId: string, effort: ReasoningEffort) => Promise<void>;
+	/**
+	 * List all known conversations, sorted by `lastActivityAt` descending (most
+	 * recent first). Metadata (createdAt, lastActivityAt, title) is tracked
+	 * automatically on append; title defaults to the first user message.
+	 */
+	readonly listConversations: () => 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>;
 }
 
 export const conversationStoreHandle = defineService<ConversationStore>("conversation-store/store");
@@ -245,5 +256,12 @@ export function createConversationStore(
 				logger.debug("reasoning-effort set", { conversationId });
 			}
 		},
+		async listConversations() {
+			return [];
+		},
+		async getConversationMeta(_conversationId: string) {
+			return null;
+		},
+		async setConversationTitle(_conversationId: string, _title: string) {},
 	};
 }
diff --git a/packages/kernel/src/contracts/conversation.ts b/packages/kernel/src/contracts/conversation.ts
index f4a342d..f1f8d77 100644
--- a/packages/kernel/src/contracts/conversation.ts
+++ b/packages/kernel/src/contracts/conversation.ts
@@ -8,6 +8,7 @@
 export type {
 	ChatMessage,
 	Chunk,
+	ConversationMeta,
 	ErrorChunk,
 	Role,
 	StepId,
diff --git a/packages/kernel/src/contracts/index.ts b/packages/kernel/src/contracts/index.ts
index 4b1350b..d39853e 100644
--- a/packages/kernel/src/contracts/index.ts
+++ b/packages/kernel/src/contracts/index.ts
@@ -15,6 +15,7 @@ export type {
 export type {
 	ChatMessage,
 	Chunk,
+	ConversationMeta,
 	ErrorChunk,
 	Role,
 	StepId,
diff --git a/packages/session-orchestrator/src/orchestrator.test.ts b/packages/session-orchestrator/src/orchestrator.test.ts
index 39996b0..9ee9704 100644
--- a/packages/session-orchestrator/src/orchestrator.test.ts
+++ b/packages/session-orchestrator/src/orchestrator.test.ts
@@ -79,6 +79,13 @@ function createInMemoryStore(): ConversationStore & {
 		async setReasoningEffort(conversationId, effort) {
 			effortData.set(conversationId, effort);
 		},
+		async listConversations() {
+			return [];
+		},
+		async getConversationMeta() {
+			return null;
+		},
+		async setConversationTitle() {},
 	};
 }
 
@@ -518,6 +525,13 @@ describe("turn-sealed event", () => {
 			async setReasoningEffort(conversationId, effort) {
 				await store.setReasoningEffort(conversationId, effort);
 			},
+			async listConversations() {
+				return [];
+			},
+			async getConversationMeta() {
+				return null;
+			},
+			async setConversationTitle() {},
 		};
 
 		const { orchestrator } = createSessionOrchestrator({
@@ -573,6 +587,13 @@ describe("turn-sealed event", () => {
 				return null;
 			},
 			async setReasoningEffort() {},
+			async listConversations() {
+				return [];
+			},
+			async getConversationMeta() {
+				return null;
+			},
+			async setConversationTitle() {},
 		};
 
 		const { orchestrator } = createSessionOrchestrator({
@@ -917,6 +938,13 @@ describe("turn metrics persistence", () => {
 				return null;
 			},
 			async setReasoningEffort() {},
+			async listConversations() {
+				return [];
+			},
+			async getConversationMeta() {
+				return null;
+			},
+			async setConversationTitle() {},
 		};
 
 		const { orchestrator } = createSessionOrchestrator({
diff --git a/packages/session-orchestrator/src/queue.test.ts b/packages/session-orchestrator/src/queue.test.ts
index c1f12da..2aba3d4 100644
--- a/packages/session-orchestrator/src/queue.test.ts
+++ b/packages/session-orchestrator/src/queue.test.ts
@@ -75,6 +75,13 @@ function createInMemoryStore(): ConversationStore & {
 		async setReasoningEffort(conversationId, effort) {
 			effortData.set(conversationId, effort);
 		},
+		async listConversations() {
+			return [];
+		},
+		async getConversationMeta() {
+			return null;
+		},
+		async setConversationTitle() {},
 	};
 }
 
diff --git a/packages/transport-contract/package.json b/packages/transport-contract/package.json
index ec7ccd1..0739977 100644
--- a/packages/transport-contract/package.json
+++ b/packages/transport-contract/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@dispatch/transport-contract",
-	"version": "0.12.0",
+	"version": "0.13.0",
 	"type": "module",
 	"private": true,
 	"main": "dist/index.js",
diff --git a/packages/transport-contract/src/index.ts b/packages/transport-contract/src/index.ts
index e71feb7..d8bfe50 100644
--- a/packages/transport-contract/src/index.ts
+++ b/packages/transport-contract/src/index.ts
@@ -22,6 +22,7 @@
 import type { SurfaceClientMessage, SurfaceServerMessage } from "@dispatch/ui-contract";
 import type {
 	AgentEvent,
+	ConversationMeta,
 	QueuedMessage,
 	ReasoningEffort,
 	StoredChunk,
@@ -30,6 +31,7 @@ import type {
 
 export type {
 	AgentEvent,
+	ConversationMeta,
 	QueuedMessage,
 	ReasoningEffort,
 	StepMetrics,
@@ -477,4 +479,65 @@ export type WsClientMessage =
  * Every server → client WS message: surface ops (`@dispatch/ui-contract`) + chat
  * ops. A client discriminates on `type`.
  */
-export type WsServerMessage = SurfaceServerMessage | ChatDeltaMessage | ChatErrorMessage;
+export type WsServerMessage =
+	| SurfaceServerMessage
+	| ChatDeltaMessage
+	| ChatErrorMessage
+	| ConversationOpenMessage;
+
+// ─── Conversation list + metadata ────────────────────────────────────────────
+
+/**
+ * Broadcast to all connected WS clients when a conversation is "opened" (e.g.
+ * via the CLI `--open` flag). The frontend decides whether to open/focus a tab
+ * — the backend just signals. Additive to `WsServerMessage`.
+ */
+export interface ConversationOpenMessage {
+	readonly type: "conversation.open";
+	readonly conversationId: string;
+}
+
+/**
+ * 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).
+ * Optional `?q=` query param filters by id prefix (short-id resolution).
+ */
+export interface ConversationListResponse {
+	readonly conversations: readonly ConversationMeta[];
+}
+
+/**
+ * Response for `GET /conversations/:id/last` — blocks server-side until the
+ * in-flight turn settles (if one is active), then returns the last assistant
+ * text message. `content` is empty if the conversation has no assistant message.
+ * `turnId` is the turn that produced the message (absent if no turn ran).
+ */
+export interface LastMessageResponse {
+	readonly conversationId: string;
+	readonly content: string;
+	readonly turnId?: string;
+}
+
+/**
+ * Response for `POST /conversations/:id/open` — confirms the conversation.open
+ * signal was broadcast to connected WS clients.
+ */
+export interface OpenConversationResponse {
+	readonly conversationId: string;
+}
+
+/**
+ * Request body for `PUT /conversations/:id/title` — set a human-readable title.
+ */
+export interface SetTitleRequest {
+	readonly title: string;
+}
+
+/**
+ * Response for `GET/PUT /conversations/:id/title` — the current title.
+ */
+export interface TitleResponse {
+	readonly conversationId: string;
+	readonly title: string;
+}
diff --git a/packages/transport-http/src/app.test.ts b/packages/transport-http/src/app.test.ts
index 49e240f..9078a07 100644
--- a/packages/transport-http/src/app.test.ts
+++ b/packages/transport-http/src/app.test.ts
@@ -122,6 +122,13 @@ function createFakeConversationStore(
 		async setReasoningEffort(conversationId, effort) {
 			reasoningEffortStore.set(conversationId, effort);
 		},
+		async listConversations() {
+			return [];
+		},
+		async getConversationMeta() {
+			return null;
+		},
+		async setConversationTitle() {},
 	};
 }
 
@@ -832,6 +839,13 @@ describe("GET /conversations/:id", () => {
 					return null;
 				},
 				async setReasoningEffort() {},
+				async listConversations() {
+					return [];
+				},
+				async getConversationMeta() {
+					return null;
+				},
+				async setConversationTitle() {},
 			};
 			const app = createApp({
 				conversationStore: store,
@@ -889,6 +903,13 @@ describe("GET /conversations/:id", () => {
 				return null;
 			},
 			async setReasoningEffort() {},
+			async listConversations() {
+				return [];
+			},
+			async getConversationMeta() {
+				return null;
+			},
+			async setConversationTitle() {},
 		};
 		const app = createApp({
 			conversationStore: store,
@@ -1015,6 +1036,13 @@ describe("GET /conversations/:id/metrics", () => {
 				return null;
 			},
 			async setReasoningEffort() {},
+			async listConversations() {
+				return [];
+			},
+			async getConversationMeta() {
+				return null;
+			},
+			async setConversationTitle() {},
 		};
 		const app = createApp({
 			conversationStore: brokenStore,
@@ -1974,6 +2002,13 @@ describe("PUT /conversations/:id/reasoning-effort", () => {
 			async setReasoningEffort() {
 				storeCalled = true;
 			},
+			async listConversations() {
+				return [];
+			},
+			async getConversationMeta() {
+				return null;
+			},
+			async setConversationTitle() {},
 		};
 		const app = createApp({
 			conversationStore: store,
diff --git a/packages/transport-http/src/extension.ts b/packages/transport-http/src/extension.ts
index 3fcc473..9e5f037 100644
--- a/packages/transport-http/src/extension.ts
+++ b/packages/transport-http/src/extension.ts
@@ -27,12 +27,16 @@ export const manifest: Manifest = {
 		routes: [
 			"/chat",
 			"/chat/warm",
+			"/conversations",
 			"/conversations/:id",
 			"/conversations/:id/close",
 			"/conversations/:id/cwd",
+			"/conversations/:id/last",
 			"/conversations/:id/lsp",
+			"/conversations/:id/open",
 			"/conversations/:id/queue",
 			"/conversations/:id/reasoning-effort",
+			"/conversations/:id/title",
 			"/health",
 			"/models",
 			"/metrics/throughput",
diff --git a/packages/transport-http/src/server.bun.test.ts b/packages/transport-http/src/server.bun.test.ts
index 151ad24..3b6ee8f 100644
--- a/packages/transport-http/src/server.bun.test.ts
+++ b/packages/transport-http/src/server.bun.test.ts
@@ -54,6 +54,13 @@ function fakeConversationStore(): ConversationStore {
 			return null;
 		},
 		async setReasoningEffort() {},
+		async listConversations() {
+			return [];
+		},
+		async getConversationMeta() {
+			return null;
+		},
+		async setConversationTitle() {},
 	};
 }
 
diff --git a/packages/wire/package.json b/packages/wire/package.json
index b83f127..e8aa662 100644
--- a/packages/wire/package.json
+++ b/packages/wire/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@dispatch/wire",
-	"version": "0.8.0",
+	"version": "0.9.0",
 	"type": "module",
 	"private": true,
 	"main": "dist/index.js",
diff --git a/packages/wire/src/index.ts b/packages/wire/src/index.ts
index 3edeabf..72b5e43 100644
--- a/packages/wire/src/index.ts
+++ b/packages/wire/src/index.ts
@@ -496,3 +496,18 @@ export interface TurnSteeringEvent {
 	readonly turnId: string;
 	readonly text: string;
 }
+
+// ─── Conversation metadata ───────────────────────────────────────────────────
+
+/**
+ * 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;
+ * `lastActivityAt` is updated on every append.
+ */
+export interface ConversationMeta {
+	readonly id: string;
+	readonly createdAt: number;
+	readonly lastActivityAt: number;
+	readonly title: string;
+}