Move common types into backend/src/types to fix Vercel bundling

Fix Vercel deployment: include common/backend dirs in function bundle

Add debug output to workflow to diagnose cron endpoint failure

switching to github actions

Update tsconfig.json

Create validate-env.ts

Create test-connection.ts

Create setup-gmail.ts

Create manual-trigger.ts

Create set-vercel-env.ps1

Update package-lock.json

Update HOW_DOES_THIS_APP_WORK.md

Create job.types.ts

Create email.types.ts

Create api.types.ts