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>

sdk/IdeaSDK/examples/hello-plugin/src/index.ts

@@ -1,15 +1,75 @@
-import type { ActivateContext, IdeAPluginModule } from "@idea/plugin-sdk";
+import type { ActivateContext, CommandDisposable, IdeAPluginModule } from "@idea/plugin-sdk";
+
+const COMMAND_ID = "hello-plugin";
+const LAYOUT_TYPE = "hello-plugin.hello-world";
+
+type HelloPluginLayoutProps = {
+  projectId?: string;
+  nodeId?: string;
+  layoutType?: string;
+  state?: unknown;
+};
+
+type LayoutRegistry = {
+  register(definition: {
+    type: string;
+    component: (props: HelloPluginLayoutProps) => string;
+  }): CommandDisposable;
+};
+
+type HelloPluginContext = ActivateContext & {
+  layouts?: LayoutRegistry;
+};
+
+let hasLoggedFirstLayoutRender = false;
+
+function HelloWorldLayout(props: HelloPluginLayoutProps): string {
+  if (!hasLoggedFirstLayoutRender) {
+    hasLoggedFirstLayoutRender = true;
+    console.info("[hello-plugin] layout first render", {
+      projectId: props.projectId,
+      nodeId: props.nodeId,
+      layoutType: props.layoutType,
+      hasState: props.state !== undefined
+    });
+  }
+
+  return "hello-world";
+}
 
 export function activate(ctx: ActivateContext): void {
-  ctx.logger.info("Hello from the IdeA hello plugin.");
-
-  const disposable = ctx.commands?.registerCommand("hello-plugin.sayHello", () => {
-    ctx.logger.info("Hello command executed.");
-    return "Hello from IdeA";
+  const pluginContext = ctx as HelloPluginContext;
+  ctx.logger.info("activating hello-plugin", {
+    pluginId: ctx.pluginId,
+    hasCommands: Boolean(pluginContext.commands),
+    hasLayouts: Boolean(pluginContext.layouts)
   });
 
-  if (disposable) {
-    ctx.subscriptions.push(disposable);
+  const commandDisposable = pluginContext.commands?.registerCommand(COMMAND_ID, () => {
+    ctx.logger.info("command executed", { commandId: COMMAND_ID });
+    return "hello-world";
+  });
+
+  if (commandDisposable) {
+    ctx.subscriptions.push(commandDisposable);
+    ctx.logger.info("command registered", { commandId: COMMAND_ID });
+  } else {
+    ctx.logger.warn("command registry unavailable", { commandId: COMMAND_ID });
+  }
+
+  const layoutDisposable = pluginContext.layouts?.register({
+    type: LAYOUT_TYPE,
+    component: HelloWorldLayout
+  });
+
+  if (layoutDisposable) {
+    ctx.subscriptions.push(layoutDisposable);
+    ctx.logger.info("layout registered", {
+      layoutType: LAYOUT_TYPE,
+      component: "hello-world"
+    });
+  } else {
+    ctx.logger.warn("layout registry unavailable", { layoutType: LAYOUT_TYPE });
   }
 }
 
@@ -18,4 +78,3 @@ const plugin: IdeAPluginModule = {
 };
 
 export default plugin;
-