fix(plex): a card offers Restart by the menu's own "started" rule

The picture read "started" off the rounded progress %, so a resume point under 1 % showed Play
while the card's menu offered "from the start". Both use `plexStarted` now.

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

@@ -208,6 +208,19 @@ describe("a started Plex card", () => {
     expect(container.querySelector(".flex-col.reveal-hover")).toBeNull();
   });
 
+  // E28 review D4: the card read "started" off the rounded progress %, the menu off the position —
+  // 20 s into a 3 h film is 0 % here and started there, so the card offered no Restart the menu had.
+  it("a resume point under 1 % still offers the Restart, as the card's menu does", () => {
+    render(
+      <PlexPosterCard
+        card={{ ...movie("in_progress"), position_seconds: 20, duration_seconds: 10800 }}
+        onOpen={vi.fn()}
+        onRestart={vi.fn()}
+      />,
+    );
+    expect(screen.getByRole("button", { name: "card.restart" })).toBeTruthy();
+  });
+
   it("a not-started or watched card keeps the one Play", () => {
     render(<PlexPosterCard card={movie("watched")} onOpen={vi.fn()} onRestart={vi.fn()} />);
     expect(screen.queryByRole("button", { name: "card.restart" })).toBeNull();