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]>

scripts/lib/deploy-smoke-browser.mjs

@@ -187,7 +187,9 @@ check(
 );
 
 // --- A module UI, imported from the API's origin -------------------------------------------------
-const moduleButton = "document.querySelector('[data-testid^=\"select-\"]')";
+// The first module link — never the Overview, which is the Dashboard's own landing page (ADR 0057).
+const moduleButton =
+  'document.querySelector(\'[data-testid^="select-"]:not([data-testid="select-overview"])\')';
 const hasModule = await waitFor(moduleButton, "a module in the Dashboard navigation");
 if (hasModule) {
   const moduleId = await evaluate(`${moduleButton}.dataset.testid.slice("select-".length)`);
@@ -224,6 +226,20 @@ if (hasModule) {
     streams.every((response) => response.status === 200),
     `every realtime stream it opened was accepted (${streams.length} opened)`,
   );
+
+  // A refresh stays on the module's own page: the proxy forwards the deep link, the API serves the
+  // Dashboard page there, and the shell mounts the same module again (ADR 0057).
+  const moduleUrl = await evaluate("location.href");
+  check(
+    moduleUrl === `${dashboardOrigin}/modules/${moduleId}`,
+    "opening the module put its own address in the address bar",
+  );
+  await navigate(moduleUrl);
+  const remounted = await waitFor(
+    `location.href === ${JSON.stringify(moduleUrl)} && ${selector(`select-${moduleId}`)}?.getAttribute("aria-current") === "page" && ${selector("module-container")}?.childElementCount > 0 && !${selector("module-loading")} && !${selector("module-error")}`,
+    "the module UI to mount again after a refresh",
+  );
+  check(remounted, `refreshing ${moduleUrl} reopens the ${moduleId} module`);
 }
 // A CORS refusal or a blocked request is always a failure. A request the page itself cancelled (a
 // module unmounting, a navigation) is not.