Testing: Add E2E Dashboard Testing Suite using Playwright

[EDOHWARES]

Description

Set up automated end-to-end dashboard tests using Playwright.

Current Problem

There are no automated front-end tests, allowing regressions in user signup, wallet connection, or trigger forms to reach production.

Proposed Solution

Implement Playwright E2E browser tests asserting core user flows and dashboard integrations.

Technical Tasks

• Install `playwright` in the frontend workspace
• Configure test execution scripts targeting multiple browser types (Chromium, Firefox, WebKit)
• Write test cases covering user authentication, form validation, and event stream visualizer
• Integrate Playwright tests into the PR validation GitHub Actions workflow

Acceptance Criteria

• Test runner starts local dev servers and runs browser automation tests successfully
• E2E checks run on every PR to main and block merging on failures
• Detailed HTML reports are generated and uploaded as build artifacts on failure

Testing Requirements

• Run Playwright locally and verify that all test scenarios complete successfully

Metadata

• Priority: Medium
• Difficulty: Medium