Fix findUsages/undo/node-lookup bugs, split Viewport and Editor, share command and inspector helpers

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

src/editor/ProjectSession.ts

@@ -0,0 +1,91 @@
+/**
+ * Loading, creating, switching and deleting projects, plus the two toolbar menus that trigger
+ * it. Talks only to the store and the editor state – no widgets of its own beyond the menus.
+ */
+import { SetActiveSceneCommand } from '../core/commands/assetCommands';
+import { listScenes } from '../core/model/Project';
+import type { ProjectStore } from '../core/store/ProjectStore';
+import { Dialog, Menu, type MenuItem, type Widget } from '../ui';
+import type { EditorState } from './state';
+
+export class ProjectSession {
+  /**
+   * `beforeSwitch` runs before a different project is loaded or the current one is deleted –
+   * a run in progress has to end first, since it holds a copy of the project being replaced.
+   */
+  constructor(private readonly state: EditorState, private readonly store: ProjectStore, private readonly beforeSwitch: () => void) {}
+
+  /** Opens the project named in the URL, else the first one on the server, else a new one. */
+  async boot(): Promise<void> {
+    const wanted = new URLSearchParams(location.search).get('project');
+    try {
+      if (wanted) {
+        await this.open(wanted);
+        return;
+      }
+      await this.openFirstOrCreate();
+    } catch (error) {
+      this.state.setNotice(`Could not load project: ${error instanceof Error ? error.message : String(error)}`);
+    }
+  }
+
+  private async open(id: string): Promise<void> {
+    this.beforeSwitch();
+    const loaded = await this.store.load(id);
+    this.state.loadProject(loaded.project, loaded.revision);
+    const url = new URL(location.href);
+    url.searchParams.set('project', id);
+    history.replaceState(null, '', url);
+  }
+
+  private async openFirstOrCreate(): Promise<void> {
+    const list = await this.store.list();
+    if (list[0]) await this.open(list[0].id);
+    else await this.create('My first project');
+  }
+
+  private async create(name: string): Promise<void> {
+    const created = await this.store.create(name);
+    await this.open(created.project.id);
+  }
+
+  private async deleteCurrent(): Promise<void> {
+    this.beforeSwitch();
+    await this.store.delete(this.state.project.id);
+    await this.openFirstOrCreate();
+  }
+
+  openProjectMenu(anchor: Widget): void {
+    const open = async () => {
+      const list = await this.store.list();
+      const items: MenuItem[] = [
+        { label: 'New project', onSelect: () => void this.create(`Project ${list.length + 1}`) },
+        ...list.map((p) => ({
+          label: p.id === this.state.project.id ? `● ${p.name}` : p.name,
+          onSelect: () => void this.open(p.id),
+          disabled: p.id === this.state.project.id,
+        })),
+        {
+          label: 'Delete this project…',
+          danger: true,
+          onSelect: () =>
+            new Dialog(`Delete project "${this.state.project.name}"?`, 'All assets and scenes are removed permanently.', [
+              { label: 'Cancel' },
+              { label: 'Delete', danger: true, onClick: () => void this.deleteCurrent() },
+            ]).openCentered(),
+        },
+      ];
+      new Menu(items).openBelow(anchor);
+    };
+    void open().catch((error) => this.state.setNotice(String(error)));
+  }
+
+  openSceneMenu(anchor: Widget): void {
+    const items: MenuItem[] = listScenes(this.state.project).map((scene) => ({
+      label: scene.id === this.state.project.activeSceneId ? `● ${scene.name}` : scene.name,
+      onSelect: () => this.state.execute(new SetActiveSceneCommand(scene.id)),
+    }));
+    if (items.length === 0) items.push({ label: 'No scenes – create one in Assets', onSelect: () => {}, disabled: true });
+    new Menu(items).openBelow(anchor);
+  }
+}