ci(config): add supabase database url and direct url environment variables

- Updated .env.example and added apps/backend/.env.example with new variables
- Modified CI workflow to include SUPABASE_DATABASE_URL and DIRECT_URL for database migration and testing jobs

Author: Arun-kushwaha007

.env.example

@@ -1,4 +1,5 @@
 SUPABASE_DATABASE_URL=
+DIRECT_URL=
 JWT_SECRET=
 JWT_REFRESH_SECRET=
 GOOGLE_CLIENT_ID=

.github/workflows/ci.yml

@@ -65,6 +65,8 @@ jobs:
       - name: Migrate Database
         env:
           DATABASE_URL: postgresql://postgres:postgres@localhost:5432/fairshare?schema=public
+          SUPABASE_DATABASE_URL: postgresql://postgres:postgres@localhost:5432/fairshare?schema=public
+          DIRECT_URL: postgresql://postgres:postgres@localhost:5432/fairshare?schema=public
           JWT_SECRET: supersecret
           STRIPE_SECRET_KEY: test_key
         run: pnpm --filter backend exec prisma db push
@@ -76,6 +78,8 @@ jobs:
         env:
           CI: true
           DATABASE_URL: postgresql://postgres:postgres@localhost:5432/fairshare?schema=public
+          SUPABASE_DATABASE_URL: postgresql://postgres:postgres@localhost:5432/fairshare?schema=public
+          DIRECT_URL: postgresql://postgres:postgres@localhost:5432/fairshare?schema=public
           JWT_SECRET: supersecret
           STRIPE_SECRET_KEY: test_key
           NEXT_PUBLIC_APP_URL: http://localhost:3000

apps/backend/.env.example

@@ -0,0 +1,15 @@
+SUPABASE_DATABASE_URL=postgresql://postgres:postgres@localhost:5432/fairshare
+DIRECT_URL=postgresql://postgres:postgres@localhost:5432/fairshare
+JWT_SECRET=fairshare_dev_jwt_secret_change_me
+JWT_REFRESH_SECRET=fairshare_dev_jwt_refresh_secret_change_me
+GOOGLE_CLIENT_ID=fairshare_dev_google_client_id
+GOOGLE_CLIENT_SECRET=fairshare_dev_google_client_secret
+REDIS_URL=redis://127.0.0.1:6380
+AWS_ACCESS_KEY_ID=fairshare_dev_aws_access_key
+AWS_SECRET_ACCESS_KEY=fairshare_dev_aws_secret
+AWS_REGION=ap-south-1
+S3_BUCKET=fairshare-dev-receipts
+STRIPE_SECRET_KEY=sk_test_fairshare_dummy_key
+STRIPE_WEBHOOK_SECRET=whsec_fairshare_dummy_webhook_secret
+CORS_ORIGINS=http://localhost:3000,http://localhost:8081,exp://*:*
+SENTRY_DSN=