test(client): add Percy visual regression testing

[AkhilTheBoss]

No description provided.

[github-actions]

Severity: Medium — journey.visual.spec.ts:17: The new *.visual.spec.ts files match Vitest’s default discovery pattern. Since vite.config.ts does not exclude visual-tests, existing npm test runs will load Playwright suites and fail with “Playwright Test did not expect test.describe.configure()/test() to be called here.” Exclude visual-tests/** from Vitest or restrict its discovery to src.

Validation was limited to static review; dependencies are not installed.