fix: Configure for ca-tor region and fix SKIP_AUTH default

- Change default region from us-south to ca-tor (uses ca.icr.io)
- Add default value for SKIP_AUTH (false) to prevent Pydantic validation errors
- Use backend/Dockerfile.backend instead of Dockerfile.codeengine for CPU-only PyTorch
- All deployments now use ca.icr.io (Toronto region) instead of us.icr.io

Fixes:
- CUDA libraries removed (CPU-only PyTorch)
- email-validator properly installed
- SKIP_AUTH validation error resolved
- Region configured for Toronto (ca-tor)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: manavgup

.github/workflows/deploy_complete_app.yml

@@ -86,7 +86,7 @@ env:
   PROJECT_NAME: rag-modulo-${{ inputs.environment || 'dev' }}
   BACKEND_APP_NAME: ${{ vars.BACKEND_APP_NAME || 'rag-modulo-backend' }}
   FRONTEND_APP_NAME: ${{ vars.FRONTEND_APP_NAME || 'rag-modulo-frontend' }}
-  IBM_CLOUD_REGION: ${{ vars.IBM_CLOUD_REGION || 'us-south' }}
+  IBM_CLOUD_REGION: ${{ vars.IBM_CLOUD_REGION || 'ca-tor' }}
   CR_NAMESPACE: ${{ vars.IBM_CR_NAMESPACE || 'rag_modulo' }}
   # ICR uses shortened region names: us-south -> us, eu-gb -> uk, ca-tor -> ca, etc.
   ICR_REGION: ${{ vars.IBM_CLOUD_REGION == 'eu-gb' && 'uk' || (vars.IBM_CLOUD_REGION == 'us-south' && 'us' ||
@@ -768,7 +768,7 @@ jobs:
           PROJECT_NAME: ${{ needs.deploy-infrastructure.outputs.project_name || env.PROJECT_NAME }}
           IBM_CLOUD_REGION: ${{ env.IBM_CLOUD_REGION }}
           IBM_CLOUD_RESOURCE_GROUP: ${{ vars.IBM_CLOUD_RESOURCE_GROUP || 'rag-modulo-deployment' }}
-          SKIP_AUTH: ${{ secrets.SKIP_AUTH }}
+          SKIP_AUTH: ${{ secrets.SKIP_AUTH || 'false' }}
           OIDC_DISCOVERY_ENDPOINT: ${{ secrets.OIDC_DISCOVERY_ENDPOINT }}
           IBM_CLIENT_ID: ${{ secrets.IBM_CLIENT_ID }}
           IBM_CLIENT_SECRET: ${{ secrets.IBM_CLIENT_SECRET }}