feat: enhance Playwright testing setup with E2E tests, new skills, and improved documentation

- Added E2E test setup in `auth_api.py` with `/e2e-seed` endpoint for database reset and test user creation.
- Integrated Playwright for end-to-end testing in the frontend with necessary dependencies in `package.json` and `package-lock.json`.
- Created Playwright configuration in `playwright.config.ts` to manage test execution and server setup.
- Developed new skills for Playwright best practices, visual regression, smoke test generation, and self-healing tests.
- Implemented new test cases for chore creation in `chores-create.smoke.spec.ts` and `chores-create.spec.ts`.
- Added page object models for `ChildEditPage` and `LandingPage` to streamline test interactions.
- Updated `.gitignore` to exclude Playwright reports and test results.
- Enhanced documentation in `copilot-instructions.md` for testing and E2E setup.

frontend/vue-app/tests/pages/LandingPage.ts

@@ -0,0 +1,13 @@
+import { Page } from '@playwright/test';
+
+export class LandingPage {
+  readonly page: Page;
+
+  constructor(page: Page) {
+    this.page = page;
+  }
+
+  async clickGetStartedFree() {
+    await this.page.getByRole('button', { name: 'Get Started Free' }).click();
+  }
+}