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

src/app/app.routes.ts

@@ -1,5 +1,6 @@
 import { Routes } from '@angular/router';
 import { languageGuard } from './guards/language.guard';
+import { projectEditorDirtyGuard } from './features/project-editor/guards/project-editor-dirty.guard';
 import { environment } from '../environments/environment';
 
 // Core routes (same across all brands)
@@ -41,7 +42,8 @@ const coreRoutes: Routes = [
   },
   {
     path: 'edit/:section',
-    loadComponent: () => import('./features/project-editor/pages/project-editor-page.component').then(m => m.ProjectEditorPageComponent)
+    loadComponent: () => import('./features/project-editor/pages/project-editor-page.component').then(m => m.ProjectEditorPageComponent),
+    canDeactivate: [projectEditorDirtyGuard]
   },
   {
     path: 'edit',