fix(ui): Lot A #151 #158 #159 (QA verte)

- #151: chevauchement des boutons dans la barre supérieure pendant une conversation agent

- #158: popup de reprise de conversation intempestive (ajout cellule / changement layout / projet)

- #159: pastille d'activité de projet

frontend/src/features/projects/ProjectTabs.test.tsx

@@ -7,7 +7,7 @@
  * read as faint text rather than a control.
  */
 import { describe, it, expect, vi } from "vitest";
-import { render, screen, fireEvent } from "@testing-library/react";
+import { render, screen, fireEvent, within } from "@testing-library/react";
 
 import type { TabItem } from "@/shared";
 import { ProjectTabs } from "./ProjectTabs";
@@ -27,6 +27,7 @@ function renderTabs(props: Partial<React.ComponentProps<typeof ProjectTabs>> = {
       onClose={props.onClose ?? vi.fn()}
       projectsPanelOpen={props.projectsPanelOpen ?? false}
       onOpenProjectsPanel={onOpenProjectsPanel}
+      activityByProjectId={props.activityByProjectId}
     />,
   );
   return { onOpenProjectsPanel };
@@ -74,3 +75,24 @@ describe("ProjectTabs add-project button (#46)", () => {
     expect(onOpenProjectsPanel).toHaveBeenCalledTimes(1);
   });
 });
+
+describe("ProjectTabs project activity dots (#159)", () => {
+  it("renders the neutral activity dot to the left of a project name by default", () => {
+    renderTabs({ items: TABS });
+
+    const tab = screen.getByRole("tab", { name: /alpha/ });
+    expect(
+      within(tab).getByTitle("alpha : aucune conversation active"),
+    ).toBeTruthy();
+  });
+
+  it("renders idle and busy project activity states", () => {
+    renderTabs({
+      items: TABS,
+      activityByProjectId: { a: "idle", b: "busy" },
+    });
+
+    expect(screen.getByTitle("alpha : conversation ouverte")).toBeTruthy();
+    expect(screen.getByTitle("beta : activité en cours")).toBeTruthy();
+  });
+});