Fix notifications opening the wrong workspace (#2331)

* fix(app): open notifications on the right host

Agent notifications previously omitted workspace ownership, so a cold target host was treated as missing and fell back to its empty home route. Carry the authoritative workspace and keep older notifications on a target-host resolver until lookup is conclusive.

* fix(app): separate notification and agent URL routing

Notifications use their authoritative workspace target directly. Stable agent URLs remain server-and-agent targets whose workspace is resolved by the agent route.

* fix(protocol): preserve notification workspace targets

Both attention message variants retain workspaceId through outbound validation so notification clicks receive the authoritative route target.

* test(app): use workspace-scoped notification target

* test(server): give notification agents workspace targets

* test(app): target notification workspace in navigation e2e

packages/app/src/utils/notification-routing.test.ts

@@ -56,13 +56,11 @@ describe("buildNotificationRoute", () => {
         agentId: "agent-1",
         workspaceId: "ws-main",
       }),
-    ).toBe("/h/srv-1/agent/agent-1");
+    ).toBe("/h/srv-1/workspace/ws-main?open=agent%3Aagent-1");
   });
 
-  it("routes directly to server-scoped agent path when both ids are present", () => {
-    expect(buildNotificationRoute({ serverId: "srv-1", agentId: "agent-1" })).toBe(
-      "/h/srv-1/agent/agent-1",
-    );
+  it("does not treat an incomplete notification as an agent URL", () => {
+    expect(buildNotificationRoute({ serverId: "srv-1", agentId: "agent-1" })).toBe("/h/srv-1");
   });
 
   it("routes to the workspace terminal tab when workspace and terminal ids are present", () => {
@@ -98,8 +96,9 @@ describe("buildNotificationRoute", () => {
     expect(
       buildNotificationRoute({
         serverId: "srv/with/slash",
+        workspaceId: "workspace-1",
         agentId: "agent with space",
       }),
-    ).toBe("/h/srv%2Fwith%2Fslash/agent/agent%20with%20space");
+    ).toBe("/h/srv%2Fwith%2Fslash/workspace/workspace-1?open=agent%3Aagent%20with%20space");
   });
 });