fix(@schematics/angular): set explicit type for the app-shell component

`ng generate app-shell` adds an `AppShell` import from `./app-shell/app-shell`, but the component it
generates inherits the workspace `type` option. In workspaces that set
`"@schematics/angular:component": { "type": "component" }`, such as those updated to v20, the
component was generated as `app-shell.component.ts` and the import failed to resolve.

Pass an empty `type`, as the library schematic does (661609e).

Refs #34449

Author: MeAkib

packages/schematics/angular/app-shell/index.ts

@@ -210,6 +210,9 @@ const appShellSchematic: RuleFactory<AppShellOptions> = createProjectSchematic(
         module: 'app.module.server.ts',
         project: options.project,
         standalone: isStandalone,
+        // The `AppShell` import added above expects the default file and class name, so the
+        // component must not inherit a `type` from the workspace.
+        type: '',
       }),
     ]);
   },

packages/schematics/angular/app-shell/index_spec.ts

@@ -136,5 +136,27 @@ describe('App Shell Schematic', () => {
       const content = tree.readContent(filePath);
       expect(content).toContain(`import { AppShell } from './app-shell/app-shell';`);
     });
+
+    it('should not inherit the component `type` from the workspace defaults', async () => {
+      // The CLI applies the `schematics` defaults of `angular.json` to nested schematics as well.
+      // Emulate it with a fresh runner so that other tests are not affected.
+      const runner = new SchematicTestRunner(
+        '@schematics/angular',
+        require.resolve('../collection.json'),
+      );
+      runner['_engineHost'].registerOptionsTransform(
+        (schematic: { name: string }, options: Record<string, unknown>) =>
+          schematic.name === 'component' && options['type'] === undefined
+            ? { ...options, type: 'component' }
+            : options,
+      );
+
+      const tree = await runner.runSchematic('app-shell', defaultOptions, appTree);
+
+      expect(tree.exists('/projects/bar/src/app/app-shell/app-shell.ts')).toBe(true);
+      expect(tree.exists('/projects/bar/src/app/app-shell/app-shell.component.ts')).toBe(false);
+      const content = tree.readContent('/projects/bar/src/app/app.config.server.ts');
+      expect(content).toContain(`import { AppShell } from './app-shell/app-shell';`);
+    });
   });
 });