feat(tickets): conservation des tickets en sprint, affichage du statut & filtres (#37)

Les tickets restent rattachés à leur sprint ; SprintManager affiche le
statut et propose des filtres via useTicketSearch. Frontend / read-query.

QA vert : tsc --noEmit exit 0, vitest 62 fichiers / 623 tests passés.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/features/tickets/tickets.test.tsx

@@ -955,4 +955,84 @@ describe("SprintManager (#11)", () => {
       expect(fresh.sprintId).toBeNull();
     });
   });
+
+  /** Seeds sprint "Holder" with one open and one closed ticket assigned. */
+  async function seedSprintWithOpenAndClosed(): Promise<void> {
+    ticket._seedSprint(PROJECT_ID, { id: "s1", order: 1, name: "Holder" });
+    const openT = await ticket.create(PROJECT_ID, {
+      title: "Open member",
+      priority: "high",
+    });
+    await ticket.setTicketSprint(PROJECT_ID, openT.ref, "s1", openT.version);
+    const closedT = await ticket.create(PROJECT_ID, {
+      title: "Closed member",
+      priority: "low",
+    });
+    const upd = await ticket.update(PROJECT_ID, closedT.ref, {
+      status: "closed",
+      expectedVersion: closedT.version,
+    });
+    await ticket.setTicketSprint(PROJECT_ID, closedT.ref, "s1", upd.version);
+  }
+
+  it("keeps closed tickets visible in the sprint with status/priority badges (#37)", async () => {
+    await seedSprintWithOpenAndClosed();
+    const dialog = await openManager();
+
+    const row = await within(dialog).findByLabelText("sprint row Holder");
+    // Both the open and the closed ticket are listed (closed is NOT hidden).
+    expect(within(row).getByText("Open member")).toBeTruthy();
+    expect(within(row).getByText("Closed member")).toBeTruthy();
+    // Each row carries its status + priority badge (scoped to the sprint row so
+    // the facet-bar labels don't collide).
+    expect(within(row).getByText("Closed")).toBeTruthy();
+    expect(within(row).getByText("Open")).toBeTruthy();
+    expect(within(row).getByText("High")).toBeTruthy();
+    expect(within(row).getByText("Low")).toBeTruthy();
+  });
+
+  it("filters the sprint tickets by status via its own facets bar (#37)", async () => {
+    await seedSprintWithOpenAndClosed();
+    const dialog = await openManager();
+
+    await within(dialog).findByText("Open member");
+    expect(within(dialog).getByText("Closed member")).toBeTruthy();
+
+    // Constrain the sprint view to Closed only → the open ticket drops out.
+    fireEvent.click(within(dialog).getByLabelText("filter status Closed"));
+    await waitFor(() =>
+      expect(within(dialog).queryByText("Open member")).toBeNull(),
+    );
+    expect(within(dialog).getByText("Closed member")).toBeTruthy();
+
+    // Clearing the facet brings the open ticket back.
+    fireEvent.click(within(dialog).getByLabelText("filter status Closed"));
+    await waitFor(() =>
+      expect(within(dialog).getByText("Open member")).toBeTruthy(),
+    );
+  });
+
+  it("sprint ticket view is independent of the main panel filter (#37)", async () => {
+    await seedSprintWithOpenAndClosed();
+
+    renderView(ticket, system, agent);
+    await waitFor(() =>
+      expect(
+        screen.getByRole("button", { name: "manage sprints" }),
+      ).toBeTruthy(),
+    );
+
+    // Constrain the MAIN Tickets panel to Open only → the closed ticket leaves
+    // the main list (there is a single main facets bar on screen at this point).
+    fireEvent.click(screen.getByLabelText("filter status Open"));
+    await waitFor(() => expect(screen.queryByText("Closed member")).toBeNull());
+
+    // Open the sprint manager: its own query ignores the main filter, so the
+    // closed ticket is still shown inside its sprint.
+    fireEvent.click(screen.getByRole("button", { name: "manage sprints" }));
+    const dialog = await screen.findByRole("dialog", { name: "manage sprints" });
+    const row = await within(dialog).findByLabelText("sprint row Holder");
+    expect(await within(row).findByText("Closed member")).toBeTruthy();
+    expect(within(row).getByText("Open member")).toBeTruthy();
+  });
 });