feat(shell): give every Dashboard page a real URL

The Dashboard had one address. The API served the page only at `/`, both
reference proxies forwarded only `/`, and the open module lived in React
state, so a refresh went back to the first module, nothing could be
bookmarked, and Back left the Dashboard (DESIGN.md §2.7).

ADR 0057 makes the address bar the source of truth:

- `/` is a host-owned Overview, now the landing page; `/modules/<id>`
  mounts that module. An id the server's navigation does not list shows
  "This page isn't available" and loads nothing; any other Dashboard
  address is a host-owned "Page not found".
- `/modules`, `/settings`, and `/account` are reserved whole, from one
  list (`@ekklesia/shell/dashboard-routes`) that the shell's router and
  the API's page routes both read. The API serves the same frozen page,
  ETag, and security headers anywhere inside them; look-alikes and other
  methods stay the sanitized 404.
- A small host-owned history replaces the selected-module state, built in
  the entry point so it stays the only file touching `window`. Navigation
  items are real links; modified clicks are left to the browser. Focus
  moves to the page after an in-place change, and the tab is named after
  the page.
- Sign-in still happens in place with no return value (ADR 0034), so a
  deep link opens its own page after sign-in.
- Both reference Caddyfiles forward the new paths; the deploy smoke now
  reloads a module's address through the real proxy and requires it to
  mount again.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

surfaces/shell/tests/auth-recovery.test.tsx

@@ -3,6 +3,7 @@ import { createRoot, type Root } from "react-dom/client";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { consumeAuthLanding, type HostAuthLanding, readAuthLanding } from "../src/auth-protocol.js";
 import { HostApp } from "../src/browser/HostApp.js";
+import { createMemoryHostHistory } from "../src/browser/host-history.js";
 import type { EkklesiaHostConfig } from "../src/host-protocol.js";
 
 /**
@@ -94,7 +95,13 @@ function platform(stub: AuthStub = {}): Platform {
 
 async function render(config: EkklesiaHostConfig, authLanding?: HostAuthLanding): Promise<void> {
   await act(async () => {
-    root.render(<HostApp config={config} {...(authLanding ? { authLanding } : {})} />);
+    root.render(
+      <HostApp
+        config={config}
+        history={createMemoryHostHistory("/")}
+        {...(authLanding ? { authLanding } : {})}
+      />,
+    );
   });
 }
 

surfaces/shell/tests/dashboard-routes.test.ts

@@ -0,0 +1,144 @@
+// @vitest-environment node
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { describe, expect, it } from "vitest";
+import {
+  DASHBOARD_PAGE_PREFIXES,
+  dashboardPath,
+  isDashboardPagePath,
+  parseDashboardPath,
+} from "../src/dashboard-routes.js";
+
+const packageDirectory = path.dirname(path.dirname(fileURLToPath(import.meta.url)));
+
+describe("the Dashboard URL space", () => {
+  it("reserves exactly the platform's page namespaces, frozen", () => {
+    expect(Object.isFrozen(DASHBOARD_PAGE_PREFIXES)).toBe(true);
+    expect(DASHBOARD_PAGE_PREFIXES).toEqual(["/modules", "/settings", "/account"]);
+  });
+
+  it("never reserves a namespace the API, display host, or host assets already own", () => {
+    for (const prefix of DASHBOARD_PAGE_PREFIXES) {
+      for (const owned of ["/api", "/display", "/assets"]) {
+        expect(prefix === owned || prefix.startsWith(`${owned}/`), prefix).toBe(false);
+        expect(owned.startsWith(`${prefix}/`), prefix).toBe(false);
+      }
+    }
+  });
+
+  it("recognizes the root and every path inside a reserved namespace as a Dashboard page", () => {
+    for (const pathname of [
+      "/",
+      "/modules",
+      "/modules/",
+      "/modules/signage",
+      "/modules/signage/timelines/abc",
+      "/settings",
+      "/settings/displays/add",
+      "/account",
+      "/account/appearance",
+    ]) {
+      expect(isDashboardPagePath(pathname), pathname).toBe(true);
+    }
+  });
+
+  it("does not claim anything outside them, including look-alike prefixes", () => {
+    for (const pathname of [
+      "",
+      "/api/v1/principal",
+      "/display/signage",
+      "/assets/ekklesia-dashboard/app.js",
+      "/modulesx",
+      "/settings-old",
+      "/accounts",
+      "/index.html",
+      "/login",
+      "modules/signage",
+    ]) {
+      expect(isDashboardPagePath(pathname), pathname).toBe(false);
+    }
+  });
+});
+
+describe("parseDashboardPath", () => {
+  it("makes the root the Overview", () => {
+    expect(parseDashboardPath("/")).toEqual({ kind: "overview" });
+  });
+
+  it("names a module page by its id, tolerating one trailing slash", () => {
+    expect(parseDashboardPath("/modules/signage")).toEqual({
+      kind: "module",
+      moduleId: "signage",
+    });
+    expect(parseDashboardPath("/modules/signage/")).toEqual({
+      kind: "module",
+      moduleId: "signage",
+    });
+  });
+
+  it("decodes a percent-encoded segment, so an id is compared as the server spells it", () => {
+    expect(parseDashboardPath("/modules/sign%61ge")).toEqual({
+      kind: "module",
+      moduleId: "signage",
+    });
+  });
+
+  it("treats every other shape as not found rather than guessing", () => {
+    for (const pathname of [
+      "",
+      "/modules",
+      "/modules/",
+      "/modules//",
+      "//modules/signage",
+      "/modules/signage//",
+      // A module's own sub-pages need a contract that does not exist yet (ADR 0057).
+      "/modules/signage/timelines",
+      "/modules/%E0%A4%A",
+      "/settings",
+      "/settings/displays",
+      "/account",
+      "/overview",
+      "/index.html",
+    ]) {
+      expect(parseDashboardPath(pathname), pathname).toEqual({ kind: "not-found" });
+    }
+  });
+});
+
+describe("dashboardPath", () => {
+  it("spells each route canonically", () => {
+    expect(dashboardPath({ kind: "overview" })).toBe("/");
+    expect(dashboardPath({ kind: "module", moduleId: "signage" })).toBe("/modules/signage");
+  });
+
+  it("encodes a module id so it can never escape its own segment", () => {
+    expect(dashboardPath({ kind: "module", moduleId: "a/../b" })).toBe("/modules/a%2F..%2Fb");
+    expect(parseDashboardPath(dashboardPath({ kind: "module", moduleId: "a/../b" }))).toEqual({
+      kind: "module",
+      moduleId: "a/../b",
+    });
+  });
+
+  it("round-trips through the parser", () => {
+    for (const route of [
+      { kind: "overview" } as const,
+      { kind: "module", moduleId: "example" } as const,
+    ]) {
+      expect(parseDashboardPath(dashboardPath(route))).toEqual(route);
+      expect(isDashboardPagePath(dashboardPath(route))).toBe(true);
+    }
+  });
+});
+
+describe("the route locator is published for the API that serves the page", () => {
+  it("is a narrow package subpath, not the shell root barrel", async () => {
+    const manifest = JSON.parse(
+      await readFile(path.join(packageDirectory, "package.json"), "utf8"),
+    ) as { exports?: Record<string, unknown> };
+    expect(manifest.exports?.["./dashboard-routes"]).toEqual({
+      import: "./dist/dashboard-routes.js",
+      types: "./dist/dashboard-routes.d.ts",
+    });
+  });
+});

surfaces/shell/tests/display-app.test.tsx

@@ -3,6 +3,7 @@ import { act, Component, type ReactElement, type ReactNode } from "react";
 import { createRoot, type Root } from "react-dom/client";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { HostApp } from "../src/browser/HostApp.js";
+import { createMemoryHostHistory } from "../src/browser/host-history.js";
 import { DisplayApp } from "../src/display/DisplayApp.js";
 import type {
   EkklesiaHostConfig,
@@ -393,7 +394,15 @@ describe("display host — full-viewport boundary", () => {
       });
     };
 
-    await act(async () => root.render(<HostApp config={config} importModule={importer} />));
+    await act(async () =>
+      root.render(
+        <HostApp
+          config={config}
+          history={createMemoryHostHistory("/modules/announcements")}
+          importModule={importer}
+        />,
+      ),
+    );
     // The management artifact rendered inside its own isolated root, not the shell's own tree.
     expect(isolatedText(container.querySelector('[data-testid="module-container"]'))).toContain(
       "announcement management",

surfaces/shell/tests/host-app.test.tsx

@@ -3,6 +3,7 @@ import { act } from "react";
 import { createRoot, type Root } from "react-dom/client";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { HostApp } from "../src/browser/HostApp.js";
+import { createBrowserHostHistory } from "../src/browser/host-history.js";
 import type { EkklesiaHostConfig } from "../src/host-protocol.js";
 import { isolatedMountTarget, isolatedText } from "./support/isolated-dom.js";
 
@@ -122,12 +123,27 @@ function artifact(id: string, version: string, options: ArtifactOptions = {}) {
   };
 }
 
+/**
+ * Renders the shell over the real (happy-dom) address bar. `path` opens that page first, exactly as
+ * a deep link or a refresh would (ADR 0057); left out, the shell opens wherever the location already
+ * is — `/`, the Overview, unless a test put something else there.
+ */
 async function render(
   config: EkklesiaHostConfig,
   importModule?: (url: string) => Promise<unknown>,
+  path?: string,
 ): Promise<void> {
+  if (path !== undefined) {
+    window.history.replaceState(null, "", path);
+  }
   await act(async () => {
-    root.render(<HostApp config={config} {...(importModule ? { importModule } : {})} />);
+    root.render(
+      <HostApp
+        config={config}
+        history={createBrowserHostHistory(window)}
+        {...(importModule ? { importModule } : {})}
+      />,
+    );
   });
 }
 
@@ -268,6 +284,11 @@ describe("Ekklesia shell — bootstrap", () => {
 });
 
 describe("Ekklesia shell — browser authentication", () => {
+  // These tests exercise a mounted module, so each opens the default fixture's own page, exactly as
+  // its deep link would (ADR 0057). The Dashboard root is the Overview and mounts nothing.
+  beforeEach(() => {
+    window.history.replaceState(null, "", "/modules/example");
+  });
   it("renders only a neutral loading state until principal resolves and fetches no navigation early", async () => {
     let releasePrincipal: (() => void) | undefined;
     const principalPending = new Promise<void>((resolve) => {
@@ -539,6 +560,11 @@ describe("Ekklesia shell — browser authentication", () => {
 });
 
 describe("Ekklesia shell — logout and session expiration", () => {
+  // These tests exercise a mounted module, so each opens the default fixture's own page, exactly as
+  // its deep link would (ADR 0057). The Dashboard root is the Overview and mounts nothing.
+  beforeEach(() => {
+    window.history.replaceState(null, "", "/modules/example");
+  });
   it("unmounts module UI and closes realtime before completing server-side logout", async () => {
     let releaseSignOut: (() => void) | undefined;
     const signOutPending = new Promise<void>((resolve) => {
@@ -856,10 +882,8 @@ describe("Ekklesia shell — Dashboard navigation", () => {
 
     const labels = [...container.querySelectorAll("h2")].map((heading) => heading.textContent);
     expect(labels).toEqual(["Planning", "Media"]);
-    const buttons = [...container.querySelectorAll("nav button")].map(
-      (button) => button.textContent,
-    );
-    expect(buttons).toEqual(["Calendar", "Livestream", "Video"]);
+    const links = [...container.querySelectorAll("nav section a")].map((link) => link.textContent);
+    expect(links).toEqual(["Calendar", "Livestream", "Video"]);
   });
 
   it("renders ungrouped modules alongside groups, under a heading", async () => {
@@ -897,14 +921,29 @@ describe("Ekklesia shell — Dashboard navigation", () => {
     expect(query("group-media")?.textContent).toBe("Media");
   });
 
-  it("selects the first module in the arranged order and marks it active", async () => {
+  it("opens on the Overview rather than choosing a module, whatever the arrangement", async () => {
+    const importModule = vi.fn(async () => artifact("video", "0.1.0"));
     await render(
       { apiBaseUrl, fetch: platformFetch({ groups: [mediaGroup(), planningGroup()] }) },
-      async (url) => artifact(url.includes("/video/") ? "video" : "other", "0.1.0"),
+      importModule,
     );
 
-    expect(query("select-video")?.getAttribute("aria-current")).toBe("page");
-    expect(query("select-livestream")?.getAttribute("aria-current")).toBeNull();
+    expect(query("select-overview")?.getAttribute("aria-current")).toBe("page");
+    expect(query("select-video")?.getAttribute("aria-current")).toBeNull();
+    expect(query("module-container")).toBeNull();
+    expect(importModule).not.toHaveBeenCalled();
+  });
+
+  it("marks the open module's link as the current page", async () => {
+    await render(
+      { apiBaseUrl, fetch: platformFetch({ groups: [mediaGroup(), planningGroup()] }) },
+      async () => artifact("livestream", "2.0.0"),
+      "/modules/livestream",
+    );
+
+    expect(query("select-livestream")?.getAttribute("aria-current")).toBe("page");
+    expect(query("select-video")?.getAttribute("aria-current")).toBeNull();
+    expect(query("select-overview")?.getAttribute("aria-current")).toBeNull();
   });
 
   it("mounts a module selected from inside a group, using the descriptor the group carried", async () => {
@@ -915,6 +954,7 @@ describe("Ekklesia shell — Dashboard navigation", () => {
         requested.push(url);
         return artifact(url.includes("/calendar/") ? "calendar" : "video", "0.1.0");
       },
+      "/modules/video",
     );
 
     await act(async () => {
@@ -972,6 +1012,11 @@ describe("Ekklesia shell — Dashboard navigation", () => {
 });
 
 describe("Ekklesia shell — mount lifecycle", () => {
+  // These tests exercise a mounted module, so each opens the default fixture's own page, exactly as
+  // its deep link would (ADR 0057). The Dashboard root is the Overview and mounts nothing.
+  beforeEach(() => {
+    window.history.replaceState(null, "", "/modules/example");
+  });
   it("keeps fixed shell tracks while module content changes size", async () => {
     await render({ apiBaseUrl, fetch: platformFetch() }, async () => artifact("example", "0.1.0"));
 
@@ -1140,6 +1185,11 @@ describe("Ekklesia shell — mount lifecycle", () => {
 });
 
 describe("Ekklesia shell — failure is host-owned", () => {
+  // These tests exercise a mounted module, so each opens the default fixture's own page, exactly as
+  // its deep link would (ADR 0057). The Dashboard root is the Overview and mounts nothing.
+  beforeEach(() => {
+    window.history.replaceState(null, "", "/modules/example");
+  });
   it("renders its own error when the artifact cannot be imported", async () => {
     await render({ apiBaseUrl, fetch: platformFetch() }, async () => {
       throw new Error("/srv/ekklesia/modules/example/dist/ui/index.js is missing");

surfaces/shell/tests/host-history.test.ts

@@ -0,0 +1,119 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { createBrowserHostHistory, createMemoryHostHistory } from "../src/browser/host-history.js";
+
+describe("the browser host history", () => {
+  beforeEach(() => {
+    window.history.replaceState(null, "", "/");
+  });
+
+  afterEach(() => {
+    window.history.replaceState(null, "", "/");
+  });
+
+  it("reads the address bar's path and moves it with real history entries", () => {
+    const history = createBrowserHostHistory(window);
+    const lengthBefore = window.history.length;
+
+    history.push("/modules/example");
+
+    expect(history.pathname()).toBe("/modules/example");
+    expect(window.location.pathname).toBe("/modules/example");
+    expect(window.history.length).toBe(lengthBefore + 1);
+  });
+
+  it("adds no entry when the page asked for is already open", () => {
+    const history = createBrowserHostHistory(window);
+    history.push("/modules/example");
+    const length = window.history.length;
+    const listener = vi.fn();
+    history.subscribe(listener);
+
+    history.push("/modules/example");
+
+    expect(window.history.length).toBe(length);
+    expect(listener).not.toHaveBeenCalled();
+  });
+
+  it("corrects the current entry in place with replace", () => {
+    const history = createBrowserHostHistory(window);
+    history.push("/modules/example/");
+    const length = window.history.length;
+
+    history.replace("/modules/example");
+
+    expect(window.location.pathname).toBe("/modules/example");
+    expect(window.history.length).toBe(length);
+  });
+
+  it("notifies after its own changes and after the browser's Back and Forward", () => {
+    const history = createBrowserHostHistory(window);
+    const listener = vi.fn();
+    const unsubscribe = history.subscribe(listener);
+
+    history.push("/modules/a");
+    history.replace("/modules/b");
+    window.dispatchEvent(new PopStateEvent("popstate"));
+    expect(listener).toHaveBeenCalledTimes(3);
+
+    unsubscribe();
+    window.dispatchEvent(new PopStateEvent("popstate"));
+    history.push("/modules/c");
+    expect(listener).toHaveBeenCalledTimes(3);
+  });
+
+  it("listens to popstate only while something is subscribed", () => {
+    const view = {
+      addEventListener: vi.fn(),
+      history: { pushState: vi.fn(), replaceState: vi.fn() },
+      location: { pathname: "/" },
+      removeEventListener: vi.fn(),
+    };
+    const history = createBrowserHostHistory(view);
+
+    const first = history.subscribe(() => undefined);
+    const second = history.subscribe(() => undefined);
+    expect(view.addEventListener).toHaveBeenCalledTimes(1);
+
+    first();
+    expect(view.removeEventListener).not.toHaveBeenCalled();
+    second();
+    expect(view.removeEventListener).toHaveBeenCalledTimes(1);
+    expect(view.removeEventListener.mock.calls[0]?.[1]).toBe(
+      view.addEventListener.mock.calls[0]?.[1],
+    );
+  });
+
+  it("stores no state object, so nothing a page put in history can be read back as authority", () => {
+    const view = {
+      addEventListener: vi.fn(),
+      history: { pushState: vi.fn(), replaceState: vi.fn() },
+      location: { pathname: "/" },
+      removeEventListener: vi.fn(),
+    };
+    const history = createBrowserHostHistory(view);
+
+    history.push("/modules/a");
+    history.replace("/modules/b");
+
+    expect(view.history.pushState).toHaveBeenCalledWith(null, "", "/modules/a");
+    expect(view.history.replaceState).toHaveBeenCalledWith(null, "", "/modules/b");
+  });
+});
+
+describe("the in-memory host history", () => {
+  it("behaves like the browser's: push truncates forward entries, go steps within bounds", () => {
+    const history = createMemoryHostHistory("/");
+    history.push("/modules/a");
+    history.push("/modules/b");
+    history.go(-1);
+    expect(history.pathname()).toBe("/modules/a");
+
+    history.push("/modules/c");
+    expect(history.entries).toEqual(["/", "/modules/a", "/modules/c"]);
+
+    history.go(-10);
+    expect(history.pathname()).toBe("/");
+    history.go(10);
+    expect(history.pathname()).toBe("/modules/c");
+  });
+});

surfaces/shell/tests/host-routing.test.tsx

@@ -0,0 +1,349 @@
+import { MODULE_UI_ABI_VERSION, type ModuleUiHostContext } from "@ekklesia/module-ui-sdk";
+import { act } from "react";
+import { createRoot, type Root } from "react-dom/client";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { HostApp } from "../src/browser/HostApp.js";
+import { createMemoryHostHistory, type MemoryHostHistory } from "../src/browser/host-history.js";
+import type { EkklesiaHostConfig } from "../src/host-protocol.js";
+import { isolatedText } from "./support/isolated-dom.js";
+
+declare global {
+  // eslint-disable-next-line no-var
+  var IS_REACT_ACT_ENVIRONMENT: boolean | undefined;
+}
+
+/**
+ * The Dashboard's URL is the source of truth for which page is open (ADR 0057). Every test drives
+ * the real shell through an in-memory history, so it can assert on the exact entries a person's
+ * Back and Forward buttons would walk.
+ */
+
+const apiBaseUrl = "https://ekklesia.example.test";
+
+let container: HTMLDivElement;
+let root: Root;
+let consoleError: ReturnType<typeof vi.spyOn>;
+
+beforeEach(() => {
+  globalThis.IS_REACT_ACT_ENVIRONMENT = true;
+  container = document.createElement("div");
+  document.body.append(container);
+  root = createRoot(container);
+  consoleError = vi.spyOn(console, "error").mockImplementation(() => undefined);
+});
+
+afterEach(async () => {
+  await act(async () => {
+    root.unmount();
+  });
+  container.remove();
+  consoleError.mockRestore();
+});
+
+function entry(id: string, name: string, version = "0.1.0") {
+  return {
+    module: {
+      api: { baseUrl: `/api/v1/modules/${id}` },
+      contributions: [],
+      display: null,
+      id,
+      permissions: [],
+      realtime: { baseUrl: `/api/v1/module-realtime/${id}` },
+      ui: { url: `/api/v1/module-ui/${id}/${version}` },
+      version,
+    },
+    name,
+  };
+}
+
+const NAVIGATION = {
+  groups: [{ id: "media", label: "Media", modules: [entry("signage", "Signage")], order: 10 }],
+  ungrouped: [entry("calendar", "Calendar", "2.0.0")],
+};
+
+function platform(options: { authenticated?: boolean } = {}) {
+  let authenticated = options.authenticated ?? true;
+  const fetchImplementation = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
+    const url = String(input);
+    if (url.endsWith("/api/auth/sign-in/email")) {
+      void init;
+      authenticated = true;
+      return Response.json({ ok: true });
+    }
+    if (url.endsWith("/api/v1/principal")) {
+      return Response.json(
+        authenticated ? { kind: "authenticated", userId: "user-1" } : { kind: "anonymous" },
+      );
+    }
+    if (url.endsWith("/api/v1/dashboard/navigation")) {
+      return authenticated
+        ? Response.json(NAVIGATION)
+        : Response.json({ code: "AUTHORIZATION_DENIED" }, { status: 403 });
+    }
+    return Response.json({ code: "NOT_FOUND" }, { status: 404 });
+  }) as unknown as typeof fetch;
+  return fetchImplementation;
+}
+
+function artifactFor(url: string) {
+  const id = url.includes("/calendar/") ? "calendar" : "signage";
+  return {
+    default: {
+      abi: MODULE_UI_ABI_VERSION,
+      id,
+      mount(element: Element, context: ModuleUiHostContext) {
+        element.textContent = `${context.moduleId} mounted`;
+        return () => {
+          element.textContent = "";
+        };
+      },
+      version: id === "calendar" ? "2.0.0" : "0.1.0",
+    },
+  };
+}
+
+interface Rendered {
+  readonly history: MemoryHostHistory;
+  readonly imported: string[];
+  readonly titles: string[];
+}
+
+async function render(
+  path: string,
+  options: { authenticated?: boolean; history?: MemoryHostHistory } = {},
+): Promise<Rendered> {
+  const history = options.history ?? createMemoryHostHistory(path);
+  const imported: string[] = [];
+  const titles: string[] = [];
+  const config: EkklesiaHostConfig = { apiBaseUrl, fetch: platform(options) };
+  await act(async () => {
+    root.render(
+      <HostApp
+        config={config}
+        history={history}
+        importModule={async (url) => {
+          imported.push(url);
+          return artifactFor(url);
+        }}
+        setDocumentTitle={(title) => titles.push(title)}
+      />,
+    );
+  });
+  return { history, imported, titles };
+}
+
+function query(testId: string): HTMLElement | null {
+  return container.querySelector<HTMLElement>(`[data-testid="${testId}"]`);
+}
+
+async function click(element: Element | null, init: MouseEventInit = {}): Promise<MouseEvent> {
+  if (!element) {
+    throw new Error("missing element");
+  }
+  const event = new MouseEvent("click", { bubbles: true, button: 0, cancelable: true, ...init });
+  await act(async () => {
+    element.dispatchEvent(event);
+  });
+  return event;
+}
+
+async function go(history: MemoryHostHistory, delta: number): Promise<void> {
+  await act(async () => {
+    history.go(delta);
+  });
+}
+
+describe("the Dashboard opens on the page its URL names", () => {
+  it("lands on the Overview at the root, and mounts no module", async () => {
+    const { imported, titles } = await render("/");
+
+    expect(query("host-overview")).not.toBeNull();
+    expect(query("host-overview")?.querySelector("h1")?.textContent).toBe("Overview");
+    expect(query("module-container")).toBeNull();
+    expect(imported).toEqual([]);
+    expect(query("select-overview")?.getAttribute("aria-current")).toBe("page");
+    expect(titles.at(-1)).toBe("Overview");
+  });
+
+  it("opens a module's page directly from its deep link — what a refresh or a bookmark does", async () => {
+    const { imported, titles } = await render("/modules/calendar");
+
+    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`]);
+    expect(isolatedText(query("module-container"))).toBe("calendar mounted");
+    expect(query("select-calendar")?.getAttribute("aria-current")).toBe("page");
+    expect(query("select-overview")?.getAttribute("aria-current")).toBeNull();
+    expect(query("host-overview")).toBeNull();
+    expect(titles.at(-1)).toBe("Calendar");
+  });
+
+  it("opens a module from inside a group exactly as one outside it", async () => {
+    const { imported } = await render("/modules/signage");
+
+    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`]);
+    expect(query("select-signage")?.getAttribute("aria-current")).toBe("page");
+  });
+
+  it("says a module page is unavailable when no navigable module has that id, and loads nothing", async () => {
+    const { imported, titles } = await render("/modules/disabled-module");
+
+    expect(query("host-module-unavailable")).not.toBeNull();
+    expect(query("module-container")).toBeNull();
+    expect(imported).toEqual([]);
+    // The address is never echoed back into the page.
+    expect(container.textContent).not.toContain("disabled-module");
+    expect(titles.at(-1)).toBe("This page isn’t available");
+    expect(query("host-go-to-overview")?.getAttribute("href")).toBe("/");
+  });
+
+  it("shows a host-owned not-found page for an address inside the Dashboard it does not know", async () => {
+    for (const path of ["/settings/displays", "/modules/calendar/events", "/account"]) {
+      await act(async () => {
+        root.unmount();
+      });
+      root = createRoot(container);
+      const { imported, titles } = await render(path);
+
+      expect(query("host-not-found"), path).not.toBeNull();
+      expect(imported, path).toEqual([]);
+      expect(titles.at(-1), path).toBe("Page not found");
+      // Nothing in the navigation claims to be the open page.
+      expect(container.querySelector('[aria-current="page"]'), path).toBeNull();
+    }
+  });
+
+  it("corrects a trailing slash to the canonical address in place, adding no history entry", async () => {
+    const { history, imported } = await render("/modules/calendar/");
+
+    expect(history.entries).toEqual(["/modules/calendar"]);
+    expect(imported).toHaveLength(1);
+  });
+
+  it("opens the deep link it was given once the person signs in, with no redirect", async () => {
+    const history = createMemoryHostHistory("/modules/calendar");
+    const { imported } = await render("/modules/calendar", { authenticated: false, history });
+    expect(query("host-login")).not.toBeNull();
+
+    const email = query("login-email") as HTMLInputElement;
+    const password = query("login-password") as HTMLInputElement;
+    const setter = Object.getOwnPropertyDescriptor(HTMLInputElement.prototype, "value")?.set;
+    await act(async () => {
+      setter?.call(email, "[email protected]");
+      email.dispatchEvent(new Event("input", { bubbles: true }));
+      setter?.call(password, "correct password");
+      password.dispatchEvent(new Event("input", { bubbles: true }));
+    });
+    await act(async () => {
+      query("host-login")
+        ?.querySelector("form")
+        ?.dispatchEvent(new Event("submit", { bubbles: true, cancelable: true }));
+    });
+
+    expect(isolatedText(query("module-container"))).toBe("calendar mounted");
+    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`]);
+    expect(history.entries).toEqual(["/modules/calendar"]);
+  });
+});
+
+describe("moving between pages", () => {
+  it("renders navigation as real links to canonical addresses", async () => {
+    await render("/");
+
+    for (const [testId, href] of [
+      ["select-overview", "/"],
+      ["select-signage", "/modules/signage"],
+      ["select-calendar", "/modules/calendar"],
+    ] as const) {
+      const link = query(testId);
+      expect(link?.tagName, testId).toBe("A");
+      expect(link?.getAttribute("href"), testId).toBe(href);
+    }
+    expect(container.querySelector('nav[aria-label="Dashboard"]')).not.toBeNull();
+  });
+
+  it("opens a page in place on an ordinary click, adding one history entry", async () => {
+    const { history, imported } = await render("/");
+
+    const event = await click(query("select-calendar"));
+
+    expect(event.defaultPrevented).toBe(true);
+    expect(history.entries).toEqual(["/", "/modules/calendar"]);
+    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`]);
+    expect(isolatedText(query("module-container"))).toBe("calendar mounted");
+  });
+
+  it("leaves a modified or middle click to the browser, so a page can open in a new tab", async () => {
+    const { history } = await render("/");
+
+    for (const init of [
+      { ctrlKey: true },
+      { metaKey: true },
+      { shiftKey: true },
+      { altKey: true },
+      { button: 1 },
+    ]) {
+      const event = await click(query("select-calendar"), init);
+      expect(event.defaultPrevented, JSON.stringify(init)).toBe(false);
+    }
+    expect(history.entries).toEqual(["/"]);
+  });
+
+  it("adds no entry when the open page's own link is clicked again", async () => {
+    const { history } = await render("/modules/calendar");
+
+    await click(query("select-calendar"));
+
+    expect(history.entries).toEqual(["/modules/calendar"]);
+  });
+
+  it("walks Back and Forward through exactly the pages that were open", async () => {
+    const { history, imported } = await render("/");
+    await click(query("select-signage"));
+    await click(query("select-calendar"));
+
+    await go(history, -1);
+    expect(isolatedText(query("module-container"))).toBe("signage mounted");
+    expect(query("select-signage")?.getAttribute("aria-current")).toBe("page");
+
+    await go(history, -1);
+    expect(query("host-overview")).not.toBeNull();
+    expect(query("module-container")).toBeNull();
+
+    await go(history, 1);
+    expect(isolatedText(query("module-container"))).toBe("signage mounted");
+    expect(imported).toEqual([
+      `${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`,
+      `${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`,
+      `${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`,
+      `${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`,
+    ]);
+  });
+
+  it("returns to the Overview from an unavailable page through its own link", async () => {
+    const { history } = await render("/modules/missing");
+
+    await click(query("host-go-to-overview"));
+
+    expect(history.entries).toEqual(["/modules/missing", "/"]);
+    expect(query("host-overview")).not.toBeNull();
+  });
+
+  it("moves focus to the new page's content after a page change, but not on first load", async () => {
+    await render("/");
+    const main = container.querySelector("main");
+    expect(main?.getAttribute("tabindex")).toBe("-1");
+    expect(document.activeElement).not.toBe(main);
+
+    await click(query("select-calendar"));
+
+    expect(document.activeElement).toBe(main);
+    expect(main?.getAttribute("aria-label")).toBe("Calendar");
+  });
+
+  it("names the browser tab after each page as it opens", async () => {
+    const { titles } = await render("/");
+    await click(query("select-signage"));
+    await click(query("select-overview"));
+
+    expect(titles).toEqual(["Overview", "Signage", "Overview"]);
+  });
+});