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.

.github/skills/playwright-visual-reg/SKILL.md

@@ -0,0 +1,12 @@
+---
+name: playwright-visual-reg
+description: Generates and manages visual regression snapshots for UI consistency.
+---
+# Playwright Visual Regression Standards
+When creating visual tests:
+
+1. **Standard Assertion**: Use `await expect(page).toHaveScreenshot('name.png');`.
+2. **Masking**: Automatically mask dynamic content (dates, usernames, or random IDs) using the `mask` option:
+   `await expect(page).toHaveScreenshot({ mask: [page.locator('.dynamic-id')] });`
+3. **Consistency**: Set `animations: 'disabled'` and `timezoneId: 'UTC'` in the generated test metadata to prevent false positives.
+4. **Update Strategy**: Instruct the user to run `npx playwright test --update-snapshots` if they intentionally changed the UI.