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)

2 files changed, 2 insertions, 0 deletions

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,