feat(frontend): host les fenêtres plugin et l'API publique windows.open

Ajoute la vue window host qui charge le layout plugin dans une fenêtre OS
détachée, expose react/react-dom/jsx-runtime hébergés sous
frontend/public/plugin-host pour que le runtime SDK y résolve React, et
câble services.windows.open() côté runtime plugin (loader/services/registry).

npm test -- --run src/adapters/window.test.ts src/app/ViewWindow.test.tsx
  src/plugins/runtime/loader.test.ts src/plugins/runtime/services.test.ts : 39/39
npm run typecheck : OK
npm run build : OK

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

frontend/src/plugins/runtime/services.ts

@@ -18,6 +18,7 @@ import type {
   PluginWorkspaceGateway,
   ProjectGateway,
   TerminalGateway,
+  WindowGateway,
   WorkStateGateway,
 } from "@/ports";
 
@@ -28,6 +29,7 @@ export interface PluginServices {
   events: EventService;
   config: ConfigDocumentService;
   terminal: TerminalService;
+  windows: WindowService;
 }
 
 export interface WorkspaceProject {
@@ -370,9 +372,32 @@ export interface TerminalService {
   close(sessionId: string): Promise<void>;
 }
 
+export interface OpenPluginWindowOptions {
+  layoutType: string;
+  state?: JsonValue;
+}
+
+export interface PluginWindow {
+  label: string;
+  url: string;
+  alreadyOpen: boolean;
+  providerPluginDisplayName: string;
+  layoutLabel: string;
+  surface: {
+    pluginId: string;
+    layoutType: string;
+    state: JsonValue;
+  };
+}
+
+export interface WindowService {
+  open(options: OpenPluginWindowOptions): Promise<PluginWindow>;
+}
+
 interface PluginServiceGatewaySet {
   project: ProjectGateway;
   terminal: TerminalGateway;
+  window: WindowGateway;
   workState: WorkStateGateway;
   focusedProject: FocusedProjectGateway;
   pluginWorkspace: PluginWorkspaceGateway;
@@ -382,6 +407,11 @@ interface PluginServiceGatewaySet {
   pluginConfig: PluginConfigGateway;
 }
 
+export interface PluginServiceScope {
+  pluginId?: string;
+  declaredLayoutTypes?: ReadonlySet<string>;
+}
+
 const DEFAULT_ROWS = 24;
 const DEFAULT_COLS = 80;
 const DEFAULT_EVENT_POLL_INTERVAL_MS = 1000;
@@ -462,7 +492,10 @@ function workspacePathMatches(watchedPath: string, eventPath: string): boolean {
   );
 }
 
-export function createPluginServices(gateways: PluginServiceGatewaySet): PluginServices {
+export function createPluginServices(
+  gateways: PluginServiceGatewaySet,
+  scope: PluginServiceScope = {},
+): PluginServices {
   async function currentProject(): Promise<WorkspaceProject | null> {
     const focused = await gateways.focusedProject.getFocusedProject();
     return focused ? toWorkspaceProject(focused) : null;
@@ -724,5 +757,28 @@ export function createPluginServices(gateways: PluginServiceGatewaySet): PluginS
     },
   };
 
-  return { workspace, tasks, tooling, events, config, terminal };
+  const windows: WindowService = {
+    async open(options) {
+      const layoutType = options.layoutType.trim();
+      if (!layoutType) {
+        throw new Error("layoutType is required");
+      }
+      if (scope.declaredLayoutTypes && !scope.declaredLayoutTypes.has(layoutType)) {
+        throw new Error(
+          `plugin "${scope.pluginId ?? "<unknown>"}" cannot open undeclared layout "${layoutType}"`,
+        );
+      }
+      const pluginId = scope.pluginId;
+      if (!pluginId) {
+        throw new Error("plugin id is required to open a plugin layout window");
+      }
+      return gateways.window.openPluginLayoutWindow({
+        pluginId,
+        layoutType,
+        state: options.state ?? null,
+      });
+    },
+  };
+
+  return { workspace, tasks, tooling, events, config, terminal, windows };
 }