feat(project-editor): warn before leaving with unsaved changes

src/app/features/project-editor/guards/project-editor-dirty.guard.ts

@@ -0,0 +1,12 @@
+import { inject } from '@angular/core';
+import { CanDeactivateFn } from '@angular/router';
+import { ProjectEditorFacade } from '../facade/project-editor.facade';
+import { ProjectEditorPageComponent } from '../pages/project-editor-page.component';
+
+export const projectEditorDirtyGuard: CanDeactivateFn<ProjectEditorPageComponent> = () => {
+  const facade = inject(ProjectEditorFacade);
+  if (!facade.dirty()) {
+    return true;
+  }
+  return window.confirm('You have unsaved changes. Leave anyway?');
+};