docs(ai): update onboarding steps (onboarding-audit-agent)

- Added `npx playwright install` instruction to `README.md` and `CONTRIBUTING.md` as it is required for smoke, visual, and e2e tests.
- Created audit report `docs/agents/task-logs/daily/2026-02-15_14-39-43_onboarding-audit-agent_completed.md`.

Co-authored-by: PR0M3TH3AN <[email protected]>

CONTRIBUTING.md

@@ -105,6 +105,12 @@ To set up the project locally:
    npm ci
    ```
 
+   If you plan to run smoke, visual, or end-to-end tests, install the Playwright browsers:
+
+   ```bash
+   npx playwright install
+   ```
+
 3. **Start the Application**:
 
    ```bash