refactor: migrate REACT_APP_ env vars to VITE_ prefix

[AugustoL]

Summary

Migrate all REACT_APP_* environment variables to Vite's native VITE_* prefix convention.

Motivation

The project uses Vite as its bundler but still follows the Create React App convention of REACT_APP_* prefixed env vars. This requires each variable to be manually added to the define map in vite.config.ts for build-time replacement. Vite natively exposes VITE_* variables via import.meta.env without any extra configuration.

Current State

Variables in vite.config.ts define map:

• REACT_APP_COMMIT_HASH
• REACT_APP_GITHUB_REPO
• REACT_APP_VERSION
• REACT_APP_OPENSCAN_NETWORKS
• REACT_APP_OPENSCAN_GROQ_AI_URL
• REACT_APP_OPENSCAN_WORKER_URL

All accessed via process.env.REACT_APP_* which Vite replaces at build time through the define option.

Proposed Solution

1. Rename all env vars from REACT_APP_* to VITE_*
2. Replace process.env.REACT_APP_* access with import.meta.env.VITE_*
3. Remove the manual define entries from vite.config.ts (Vite handles VITE_* automatically)
4. Update CI/CD configs (GitHub Actions, Netlify) to use the new variable names
5. Update deployment scripts (scripts/build-production.sh, scripts/build-staging.sh)
6. Update documentation if any references exist

Acceptance Criteria

• All REACT_APP_* variables renamed to VITE_*
• Code uses import.meta.env.VITE_* instead of process.env.REACT_APP_*
• define map in vite.config.ts cleaned up (only non-env entries remain)
• CI/CD and deployment configs updated
• Application works correctly in dev, staging, and production