Add timer app

[setnilson]

Summary

Builds the requested Sarah app workspace as a Datadog App timer under apps/sarah-s-app-wed-aug-12-1-34-27-pm. The app gives users a focused countdown timer with presets, custom duration inputs, and controls for start, pause, reset, and adding one minute.

Changes

• Added a Vite/React app workspace in apps/sarah-s-app-wed-aug-12-1-34-27-pm.
• Implemented countdown state with accurate target-time ticking, completion handling, presets, custom minute/second inputs, and elapsed/remaining stats.
• Added responsive CSS for desktop and mobile layouts with a progress ring and compact phone controls.
• Configured the app Vite plugin to resolve DD_SITE from the root workspace manifest and keep Vite cache under the root node_modules tree.
• Regenerated package-lock.json for the new workspace package and dependency links.

Testing

• npm install --package-lock-only --ignore-scripts
• npm ci --ignore-scripts
• npm ls react react-dom --workspaces --all
• npm run typecheck -w apps/sarah-s-app-wed-aug-12-1-34-27-pm
• npm run lint -w apps/sarah-s-app-wed-aug-12-1-34-27-pm
• npm run build -w apps/sarah-s-app-wed-aug-12-1-34-27-pm
• Playwright loaded http://localhost:5173/, verified start/countdown/pause/reset behavior, confirmed no browser errors or warnings, and captured desktop/mobile screenshots.

---

PR by Bits - View session in Datadog

Comment @datadog-staging to request changes

[datadog-staging]

View session in Datadog

Bits Code status: ✅ Done

Comment @datadog-staging to request changes

[datadog-staging]

I can only run on private repositories.