chore: remove CRA and move to a pure esbuild build

[dmacvicar]

Summary

react-scripts is deprecated and its dependencies are a source of vulnerabilities. This PR moves the build to a pure esbuild more in line with other projects. After this change, npm audit goes from 29 vulnerabilities to just 2.

• replace react-scripts with a custom esbuild toolchain aligned with the other UI projects
• add ui/scripts/esbuild.{common,build,dev}.mjs to drive production builds and the dev server, copying
  public/ assets into build/
• wire npm scripts (dev, build, typecheck, test) and Makefile hot-reload target to the new workflow; drop CRA presets from package.json
• keep Docker packaging unchanged by continuing to emit ui/build/, and add the missing uuid dependency so esbuild can bundle configuration helpers
• regenerate package-lock.json after the dependency churn; no CRA files remain

Tested:

• Smoke test with Docker Desktop
• Hot reload setting EXTRA_CORS_ALLOWED_ORIGINS in the configuration
• Verified bundled size

Caveats / Follow-ups

• npm run typecheck now fails on existing MUI component prop typings (ConfirmableButton, Menu). CRA never surfaced these; we should either adjust the types or downgrade the checks before gating CI.

Disclaimer: Codex agent helped heavily here

[Pive01]

To work it works as I could build the image and install it in docker desktop successfully.
I've left a few comments on things that I don't think we actually need but didn't verify all the packages changes one by one, which is where I trust your judgment. Let me know if you want me to go over the comments and address them or you wish to do it yourself :)

[Pive01]

LGTM!
Thanks for tackling this 🥳