Migrate react-frontend from Create React App to Vite

[vmuralictr]

Problem

The react-frontend is built on Create React App (CRA), which has
been officially unmaintained since early 2023. This has two direct
consequences for this project:

1. It is a root cause of many vulnerabilities in Complete security updates to React front-end packages #244 — several
   high/critical CVEs are locked inside react-scripts and cannot
   be patched without leaving CRA
2. Dev server startup is significantly slower than modern alternatives
3. There is no supported upgrade path — CRA is effectively abandoned

Proposed Solution

Migrate react-frontend from CRA to Vite, which is the current
community standard for React tooling.

Benefits

• Eliminates the react-scripts vulnerability surface entirely
• Significantly faster HMR (Hot Module Replacement) during development
• Actively maintained with regular security updates
• Smaller node_modules footprint
• Compatible with the existing React + Tailwind CSS setup

Migration Scope

• Replace react-scripts with vite and @vitejs/plugin-react
• Update package.json scripts (start → dev, build, preview)
• Add vite.config.js
• Update index.html entry point (Vite serves from root, not public/)
• Verify all existing components render correctly post-migration
• Update docs/Installation.md with new dev setup instructions

Dependencies

Should be done after #286 (test suite) is in place, so we can
verify nothing breaks during migration.

Happy to guide anyone who picks this up.