feat(frontend): système de plugins — runtime, menus, layouts custom (#43)

Lots F1-F4 : runtime de chargement/registre plugin, extension des menus
existants, panneau de gestion des plugins, types de layout custom
(sélecteur, fallback, cellule dédiée) branchés sur le port plugin.
Suite npm typecheck/test verte (947/947).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/features/plugins/plugins.test.tsx

@@ -0,0 +1,102 @@
+/**
+ * F2 — `PluginsPanel` (ticket #43, carnet §10 F2 acceptance criteria): install
+ * from archive/directory with pre-install review, full-trust mention visible,
+ * enable/disable/uninstall flows, and `restartRequired` rendered.
+ */
+import { describe, it, expect } from "vitest";
+import { render, screen, waitFor, fireEvent, within } from "@testing-library/react";
+
+import { MockPluginGateway, MockSystemGateway } from "@/adapters/mock";
+import type { Gateways } from "@/ports";
+import { DIProvider } from "@/app/di";
+import { PluginsPanel } from "./PluginsPanel";
+
+function renderPanel(plugin?: MockPluginGateway, system?: MockSystemGateway) {
+  const p = plugin ?? new MockPluginGateway();
+  const s = system ?? new MockSystemGateway();
+  const gateways = { plugin: p, system: s } as unknown as Gateways;
+  return {
+    plugin: p,
+    system: s,
+    ...render(
+      <DIProvider gateways={gateways}>
+        <PluginsPanel />
+      </DIProvider>,
+    ),
+  };
+}
+
+describe("PluginsPanel", () => {
+  it("shows an empty state with no plugins installed", async () => {
+    renderPanel();
+    expect(await screen.findByText("Aucun plugin installé.")).toBeTruthy();
+  });
+
+  it("installs from an archive via the review dialog, mentioning full-trust", async () => {
+    renderPanel();
+    await screen.findByText("Aucun plugin installé.");
+
+    fireEvent.click(screen.getByRole("button", { name: "Installer depuis une archive…" }));
+
+    const dialog = await screen.findByRole("dialog");
+    expect(within(dialog).getByText(/full-trust/)).toBeTruthy();
+
+    fireEvent.click(within(dialog).getByRole("button", { name: "Installer" }));
+
+    // The installed plugin now shows in the list, restart required (carnet §1.4).
+    expect(await screen.findByText("mock-plugin")).toBeTruthy();
+    expect(screen.getByText("Redémarrage requis")).toBeTruthy();
+    expect(screen.getByText("Activé")).toBeTruthy();
+  });
+
+  it("disables an installed plugin after confirmation", async () => {
+    const plugin = new MockPluginGateway();
+    plugin._seedPlugin({
+      id: "dev.acme.one",
+      displayName: "Acme One",
+      version: "1.0.0",
+      sourceKind: "archive",
+      lifecycleState: "enabled",
+      enabled: true,
+      pendingUninstall: false,
+      restartRequired: false,
+      trustLevel: "full",
+      contributionSummary: { topLevelMenus: 0, menuItems: 0, layouts: 0, mcpServers: 0 },
+    });
+    renderPanel(plugin);
+
+    await screen.findByText("Acme One");
+    fireEvent.click(screen.getByRole("button", { name: "Désactiver" }));
+
+    const dialog = await screen.findByRole("dialog");
+    fireEvent.click(within(dialog).getByRole("button", { name: "Désactiver" }));
+
+    await waitFor(() => expect(screen.getByText("Désactivé")).toBeTruthy());
+  });
+
+  it("uninstalls an installed plugin after confirmation", async () => {
+    const plugin = new MockPluginGateway();
+    plugin._seedPlugin({
+      id: "dev.acme.two",
+      displayName: "Acme Two",
+      version: "1.0.0",
+      sourceKind: "directory",
+      lifecycleState: "enabled",
+      enabled: true,
+      pendingUninstall: false,
+      restartRequired: false,
+      trustLevel: "full",
+      contributionSummary: { topLevelMenus: 0, menuItems: 0, layouts: 0, mcpServers: 0 },
+    });
+    renderPanel(plugin);
+
+    await screen.findByText("Acme Two");
+    fireEvent.click(screen.getByRole("button", { name: "Désinstaller" }));
+
+    const dialog = await screen.findByRole("dialog");
+    fireEvent.click(within(dialog).getByRole("button", { name: "Désinstaller" }));
+
+    await waitFor(() => expect(screen.queryByText("Acme Two")).toBeNull());
+    expect(await screen.findByText("Aucun plugin installé.")).toBeTruthy();
+  });
+});