feat(ci): use APP_ENV variable for generateConfig in CI #3795

Problem

npm run generateConfig in CI.yml runs without NODE_ENV, defaulting to development.config.js. Downstream projects (lou, comes, montaine) have their own config files (e.g. lou.config.js) with project-specific endpoints and settings.

Solution

Add APP_ENV variable support to the generateConfig step:

- run: npm run generateConfig
  env:
    NODE_ENV: ${{ vars.APP_ENV || 'development' }}

Each downstream project sets APP_ENV as a repo variable (e.g. APP_ENV=lou). Default stays development for the devkit itself.

Impact

• Zero breaking change — defaults to current behavior
• Downstream projects configure via repo variable, no workflow edits needed
• Also apply to E2E job's Vue dev server step (NODE_ENV: ${{ vars.APP_ENV || 'test' }})