feat(nav): tabs, list views and name searches are named in the address

Settings, Configuration and Users name their tab (stab/cfgtab/utab); a link's tab wins and a tab pre-selected
while its page is on screen now switches it. A playlist's sort, filters and grouping (plsort/plf/plgroup), the
Files sort (fsort, always written) and the name searches of Channels, Files, Playlists and Plex (cq/fq/plq/pq+pqf)
reopen from the address; the searches are written once the typing pauses.

frontend/src/modules/files/Files.menu.dom.test.tsx

@@ -20,6 +20,7 @@ import {
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { api, type FileFolder, type LibraryFile } from "../../lib/api";
 import { formatDateTime } from "../../lib/format";
+import { qk } from "../../lib/queryKeys";
 import {
   ALL_FILES,
   FilesActionsContext,
@@ -172,6 +173,8 @@ const HUB = folder(4, { kind: "hub", retention_days: null, count: 0 });
 afterEach(() => {
   cleanup();
   vi.restoreAllMocks();
+  // The page names its sort in the address: one case's sort must not open the next.
+  window.history.replaceState(null, "", "/");
   mocks.confirm.mockClear();
   mocks.keys = [];
   mocks.fetching = false;
@@ -513,6 +516,8 @@ describe("Files · a library past the list's cap", { timeout: 30_000 }, () => {
     fireEvent.click(nameHeader());
     expect(screen.getByText("files.countFirst")).toBeTruthy();
     cleanup();
+    // A fresh page: the address names the sort picked above.
+    window.history.replaceState(null, "", "/");
 
     // A search with no sort of the server's: it answers the newest matches first.
     mount(ALL_FILES, vi.fn(), "clip");
@@ -806,6 +811,67 @@ describe("Files · the view", () => {
   });
 });
 
+// The URL is the view: the sort is named in the address, so a bookmark opens the list in its order.
+// Always written, the list's own order too: a page opened without one takes the account's sort.
+describe("Files · the sort in the address", () => {
+  const fsort = () => new URLSearchParams(window.location.search).get("fsort");
+  const order = () =>
+    [...document.querySelectorAll<HTMLElement>("[data-nav-index]")].map(
+      (r) => r.textContent?.match(/Clip \d/)?.[0],
+    );
+  const three = () => [
+    file(2, { ready_at: "2026-10-05T10:00:00Z" }),
+    file(3, { ready_at: "2026-10-12T10:00:00Z" }),
+    file(4, { ready_at: "2026-10-03T10:00:00Z" }),
+  ];
+  // The account's sort, as the server says it.
+  function mountWithSort(sort: unknown) {
+    const qc = new QueryClient();
+    qc.setQueryData(qk.me(), { preferences: { filesSort: sort } });
+    render(
+      <QueryClientProvider client={qc}>
+        <FilesActionsContext.Provider
+          value={{ setSearch: vi.fn(), setView: vi.fn(), openFile: vi.fn(), consumeFocus: vi.fn() }}
+        >
+          <FilesStateContext.Provider
+            value={{ search: "", view: ALL_FILES, focus: null, arrived: null }}
+          >
+            <Files />
+          </FilesStateContext.Provider>
+        </FilesActionsContext.Provider>
+      </QueryClientProvider>,
+    );
+  }
+
+  it("names the sort picked, and the list's own order", () => {
+    vi.spyOn(api, "savePrefs").mockResolvedValue({} as never);
+    mocks.files = three();
+    mocks.folders = [YT];
+    mount();
+    expect(fsort()).toBe("none");
+    fireEvent.click(screen.getByRole("button", { name: /files\.columns\.added/ }));
+    expect(fsort()).toBe("added:asc");
+  });
+
+  it("opens in the order a link names, over the account's", () => {
+    mocks.files = three();
+    mocks.folders = [YT];
+    window.history.replaceState(null, "", "/?page=files&fsort=added:asc");
+    mountWithSort({ key: "added", dir: "desc" });
+    expect(order()).toEqual(["Clip 4", "Clip 2", "Clip 3"]);
+    expect(fsort()).toBe("added:asc");
+  });
+
+  it("a link to the list's own order is not sorted by the account's", () => {
+    mocks.files = three();
+    mocks.folders = [YT];
+    window.history.replaceState(null, "", "/?page=files&fsort=none");
+    mountWithSort({ key: "added", dir: "asc" });
+    expect(order()).not.toEqual(["Clip 4", "Clip 2", "Clip 3"]);
+    expect(fsort()).toBe("none");
+  });
+});
+
 describe("Files · the grid", () => {
   // The layout is a pref, saved to the server; nothing here is about that.
   const quiet = () => vi.spyOn(api, "savePrefs").mockResolvedValue({} as never);