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.

2 files changed, 12 insertions, 1 deletions

diff --git a/src/core/wire/conformance.test.ts b/src/core/wire/conformance.test.ts
index 2fdd3cb..f5d6608 100644
--- a/src/core/wire/conformance.test.ts
+++ b/src/core/wire/conformance.test.ts
@@ -139,9 +139,18 @@ describe("classifies every WsServerMessage type", () => {
 				event: { type: "done" as const, conversationId: "c", turnId: "t", reason: "r" },
 			},
 			{ type: "chat.error" as const, message: "e" },
+			{ type: "conversation.open" as const, conversationId: "c1" },
 		];
 		const labels = msgs.map(assertWsServerMessageExhaustive);
-		expect(labels).toEqual(["catalog", "surface", "update", "error", "chat.delta", "chat.error"]);
+		expect(labels).toEqual([
+			"catalog",
+			"surface",
+			"update",
+			"error",
+			"chat.delta",
+			"chat.error",
+			"conversation.open",
+		]);
 	});
 });
 
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;
 	}