fix(plugins): isole les menus plugin et durcit hello-plugin SDK contre la rechute #120

Requalification Architect du 2026-08-01: le crash INTERFACE INTERROMPUE au
chargement d'un plugin (menu + item) remonte via ProjectsView -> usePluginMenus
-> MenuBar jusqu'à RootErrorBoundary, quel que soit le plugin (ancien ou
reconstruit via SDK).

- usePluginMenus isole la résolution/conversion des contributions plugin :
  toute erreur retombe sur [] au lieu de propager.
- ProjectsView sépare les menus natifs des menus enrichis par plugin et rend
  MenuBar derrière une error boundary locale (fallback menus natifs seuls).
- hello-plugin (SDK) et les tests d'installation associés durcis en cohérence.

Bookkeeping ticket #120 uniquement (issue.md, carnet.md) ; les fichiers
counter.json/index.json et le dossier tickets/122/ restent hors commit car
une collision de numérotation #122 existe entre cette base et
feature/ticket120-hello-plugin-install-path-audit (deux tickets différents
revendiquent #122) — à arbitrer avant de committer le bookkeeping global.

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

frontend/src/plugins/runtime/loader.test.ts

@@ -178,12 +178,16 @@ describe("loadPlugins", () => {
     expect(registry.get("com.example.hello-plugin")).toBeUndefined();
   });
 
-  it("loads the hello-plugin contribution shape with omitted optional arrays", async () => {
+  it("loads the hello-plugin command and layout contribution shape", async () => {
     const bundle = dataUrl(`
       export function activate(ctx) {
-        ctx.commands.registerCommand("hello-plugin.sayHello", () => {
+        ctx.commands.registerCommand("hello-plugin", () => {
           globalThis.__helloArchiveCommandRan = true;
         });
+        ctx.layouts.register({
+          type: "hello-plugin.hello-world",
+          component: () => "hello-world",
+        });
       }
     `);
     const { registry, failures } = await loadPlugins(
@@ -193,13 +197,20 @@ describe("loadPlugins", () => {
           displayName: "Hello Plugin",
           bundleUrl: bundle,
           contributes: {
-            menus: [{ id: "hello-plugin.menu", label: "Hello", topLevel: true }],
+            menus: [{ id: "hello-plugin.menu", label: "Hello Plugin", topLevel: true }],
             menuItems: [
               {
-                id: "hello-plugin.sayHello.item",
+                id: "hello-plugin.command.item",
                 targetMenuId: "hello-plugin.menu",
-                label: "Say Hello",
-                command: "hello-plugin.sayHello",
+                label: "hello-plugin",
+                command: "hello-plugin",
+              },
+            ],
+            layouts: [
+              {
+                type: "hello-plugin.hello-world",
+                label: "hello-world",
+                component: "hello-world",
               },
             ],
           } as unknown as PluginContributionDto,
@@ -209,10 +220,22 @@ describe("loadPlugins", () => {
     );
 
     expect(failures).toEqual([]);
-    expect(registry.get("com.example.hello-plugin")?.contributes.layouts).toEqual([]);
+    expect(registry.get("com.example.hello-plugin")?.contributes.layouts).toEqual([
+      {
+        type: "hello-plugin.hello-world",
+        label: "hello-world",
+        component: "hello-world",
+      },
+    ]);
     expect(registry.get("com.example.hello-plugin")?.contributes.mcpServers).toEqual([]);
-    await registry.runCommand("com.example.hello-plugin", "hello-plugin.sayHello");
+    await registry.runCommand("com.example.hello-plugin", "hello-plugin");
     expect((globalThis as Record<string, unknown>).__helloArchiveCommandRan).toBe(true);
+    const Layout = registry.layoutComponent(
+      "com.example.hello-plugin",
+      "hello-plugin.hello-world",
+    );
+    expect(Layout).toBeDefined();
+    expect((Layout as unknown as () => string)()).toBe("hello-world");
   });
 
   it("confines a malformed runtime catalog entry and still loads healthy plugins", async () => {

frontend/src/plugins/runtime/loader.ts

@@ -301,8 +301,20 @@ export async function loadPlugins(
     entries.map((entry) => loadOne(entry, gateways, resolvedOptions)),
   );
   for (const result of results) {
-    if ("failure" in result) failures.push(result.failure);
-    else registry.add(result.plugin);
+    if ("failure" in result) {
+      failures.push(result.failure);
+      console.warn(
+        `[plugins] load failed plugin=${result.failure.pluginId}: ${result.failure.reason}`,
+      );
+    } else {
+      registry.add(result.plugin);
+    }
+  }
+
+  if (entries.length > 0) {
+    console.info(
+      `[plugins] load complete loaded=${registry.list().length} failed=${failures.length}`,
+    );
   }
 
   return { registry, failures };