fix(plex): make the header Discover/Browse toggle clickable

The floating header wrapper is pointer-events-none (so clicks fall through its empty
area to the content below); every interactive child must re-enable pointer events.
PlexViewToggle rendered its SegmentedToggle without the pointer-events-auto wrapper the
sibling PlexScopeToggle has, so the whole Discover/Browse switch was click-dead — the
buttons rendered and were correctly wired, but no real mouse click ever reached them.

Add `className="pointer-events-auto shrink-0"` to the toggle and a regression test that
asserts the root re-enables pointer events (plus the render/onChange/hide-on-deeper-view
contract). Verified live on localdev: real clicks now switch Discover⟷Browse (?v=browse)
in both directions; a header-wide hit-test audit shows no other dead controls.

Gate: tsc/lint/knip/prettier clean, 418 vitest.

frontend/src/components/PlexViewToggle.dom.test.tsx

@@ -0,0 +1,65 @@
+// @vitest-environment jsdom
+//
+// Contract of the header Discover ⟷ Browse toggle. The floating header wrapper is pointer-events-none,
+// so the toggle MUST re-enable pointer events on its root or it is click-dead (the bug this test guards
+// against). Also: it only renders on the two title-browse views, marks the active one, and drives
+// PlexBrowse's sub-view through the bridge. i18n is key-passthrough; the bridge is mocked.
+import { describe, it, expect, afterEach, beforeEach, vi } from "vitest";
+import { render, screen, fireEvent, cleanup } from "@testing-library/react";
+
+vi.mock("react-i18next", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("react-i18next")>();
+  return { ...actual, useTranslation: () => ({ t: (key: string) => key }) };
+});
+
+const controls = { kind: "discover" as string, open: vi.fn() };
+vi.mock("./PlexViewBridge", () => ({
+  usePlexViewControls: () => controls,
+}));
+
+import PlexViewToggle from "./PlexViewToggle";
+
+beforeEach(() => {
+  controls.kind = "discover";
+  controls.open.mockReset();
+});
+afterEach(cleanup);
+
+describe("PlexViewToggle", () => {
+  it("re-enables pointer events on its root (the header wrapper is pointer-events-none)", () => {
+    const { container } = render(<PlexViewToggle />);
+    // Without this class the whole toggle is click-dead inside the pointer-events-none header.
+    expect(container.querySelector(".pointer-events-auto")).not.toBeNull();
+  });
+
+  it("renders the two options with the current view pressed", () => {
+    render(<PlexViewToggle />);
+    const btns = [
+      ...screen.getByRole("group", { name: "plex.view.label" }).querySelectorAll("button"),
+    ];
+    expect(btns.map((b) => b.textContent)).toEqual(["plex.discover.tab", "plex.view.browse"]);
+    const pressed = btns
+      .filter((b) => b.getAttribute("aria-pressed") === "true")
+      .map((b) => b.textContent);
+    expect(pressed).toEqual(["plex.discover.tab"]);
+  });
+
+  it("opens the grid view when Browse is picked", () => {
+    render(<PlexViewToggle />);
+    fireEvent.click(screen.getByRole("button", { name: "plex.view.browse" }));
+    expect(controls.open).toHaveBeenCalledWith({ kind: "grid" });
+  });
+
+  it("opens the discover view when Discover is picked from the grid", () => {
+    controls.kind = "grid";
+    render(<PlexViewToggle />);
+    fireEvent.click(screen.getByRole("button", { name: "plex.discover.tab" }));
+    expect(controls.open).toHaveBeenCalledWith({ kind: "discover" });
+  });
+
+  it("renders nothing on a deeper view (no Discover/Browse choice there)", () => {
+    controls.kind = "playlists";
+    const { container } = render(<PlexViewToggle />);
+    expect(container.firstChild).toBeNull();
+  });
+});

frontend/src/components/PlexViewToggle.tsx

@@ -11,9 +11,13 @@ export default function PlexViewToggle() {
   // Only the two title-browse views host the Discover/Browse choice; deeper views (show/info/person/…)
   // and the playlists/collections browse surfaces hide it.
   if (!ctl || (ctl.kind !== "discover" && ctl.kind !== "grid")) return null;
+  // The floating header wrapper is pointer-events-none (so clicks fall through its empty area to the
+  // content below); every interactive child must re-enable pointer events or it is click-dead — the
+  // sibling PlexScopeToggle does the same.
   return (
     <SegmentedToggle
       size="md"
+      className="pointer-events-auto shrink-0"
       ariaLabel={t("plex.view.label")}
       options={[
         { value: "discover", label: t("plex.discover.tab") },