test(ui): add Playwright component tests for MessageTimeline and SessionView

[pixellos]

Summary

Adds Playwright component test infrastructure and initial tests for the @codenomad/ui package.

Changes

• Test infrastructure: Playwright CT config, test provider (test-utils.tsx), and shims
• MessageTimeline tests: Empty segments, diverse segment rendering, click events, 1000-item virtualization perf test
• SessionView tests: Rendering with loading state, session display, prompt input visibility
• Dev dependency: Added @sand4rt/experimental-ct-solid for SolidJS component testing

How to run

cd packages/ui
npx playwright test -c playwright-ct.config.ts

[github-actions]

PR builds are available as GitHub Actions artifacts:

https://github.com/NeuralNomadsAI/CodeNomad/actions/runs/23538671140

Artifacts expire in 7 days.
Artifacts: (none found on this run)

[shantur]

@pixellos - Thanks.
The builds are failing currently with

npm error
npm error `npm ci` can only install packages when your package.json and package-lock.json or npm-shrinkwrap.json are in sync. Please update your lock file with `npm install` before continuing.
npm error

[pixellos]

Working on it, just installed WSL to create linux native package locks.

[github-actions]

PR builds are available as GitHub Actions artifacts:

https://github.com/NeuralNomadsAI/CodeNomad/actions/runs/23539594100

Artifacts expire in 7 days.
Artifacts: (none found on this run)

[github-actions]

PR builds are available as GitHub Actions artifacts:

https://github.com/NeuralNomadsAI/CodeNomad/actions/runs/23540099060

Artifacts expire in 7 days.
Artifacts: (none found on this run)

[github-actions]

PR builds are available as GitHub Actions artifacts:

https://github.com/NeuralNomadsAI/CodeNomad/actions/runs/23540663906

Artifacts expire in 7 days.
Artifacts: (none found on this run)

[shantur]

@CodeNomadBot

I want you to perform the gatekeeper checks for latest PR state

check for regressions
check for better possible implementations
Be the PR gatekeeper

[shantur]

@CodeNomadBot

Check again

[pixellos]

Still fighting with the linux build, but i'm getting closer.