feat: Journals joins the Agents hub — third tab (#559)

* feat(panel): Journals joins the Agents hub as its third tab

* docs(map): Journals tab on the Agents hub; registry retargets

---------

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

panel/src/app/(dashboard)/journals/__tests__/page.test.tsx

@@ -0,0 +1,13 @@
+import { describe, it, expect, vi } from "vitest";
+
+const { redirect } = vi.hoisted(() => ({ redirect: vi.fn() }));
+vi.mock("next/navigation", () => ({ redirect }));
+
+import JournalsPage from "../page";
+
+describe("JournalsPage", () => {
+  it("redirects to the Agents hub's Journals tab", () => {
+    JournalsPage();
+    expect(redirect).toHaveBeenCalledWith("/agents?tab=journals");
+  });
+});