feat(ws): handle conversation.open broadcast — open/focus tab from CLI --open

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

- WS adapter (logic.ts + index.ts): parse + route the new top-level
  "conversation.open" WsServerMessage to an onConversationOpen handler
- app store: openConversation(id) opens (or focuses) a tab — creates a chat
  store, loads history, subscribes to live turns, creates+selects the tab
- conformance guard + WS adapter tests cover the new type
- backend also shipped conversation metadata endpoints (GET /conversations,
  GET /conversations/:id/last, GET/PUT /conversations/:id/title) — mirrored
  but not yet consumed by the FE

682 tests green.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/core/wire/conformance.ts b/src/core/wire/conformance.ts
index 6e87e5c..05a15aa 100644
--- a/src/core/wire/conformance.ts
+++ b/src/core/wire/conformance.ts
@@ -81,6 +81,8 @@ export function assertWsServerMessageExhaustive(msg: WsServerMessage): string {
 			return "chat.delta";
 		case "chat.error":
 			return "chat.error";
+		case "conversation.open":
+			return "conversation.open";
 		default:
 			return msg satisfies never;
 	}