[DTOSS-11410] - fix(infra): Fix smoke test for production apex domain configuration

[josielsouzanordcloud]

Fix smoke test for production apex domain configuration

Description

Fixed smoke test script to support apex domain configuration for production environment. The smoke test was failing because it was constructing URLs as {env}.{domain}/sha for all environments, but production uses an apex domain configuration (use_apex_domain = true) which requires just {domain}/sha.

Changes Made

1. Updated smoke test script

• Added USE_APEX_DOMAIN parameter (5th parameter) to container_app_smoke_test.sh
• Added conditional logic to construct URLs based on apex domain flag:
  • When USE_APEX_DOMAIN=true: uses https://{DNS_ZONE_NAME}/sha
  • When USE_APEX_DOMAIN=false: uses https://{ENV_CONFIG}.{DNS_ZONE_NAME}/sha
  • For PR environments: always uses https://pr-{PR_NUMBER}.{DNS_ZONE_NAME}/sha
• Defaults to false for backward compatibility

2. Updated GitHub workflow

• Modified .github/workflows/stage-4-deploy.yaml to extract use_apex_domain from environment's variables.tfvars
• Passes the use_apex_domain value as 5th parameter to smoke test script
• Falls back to "false" if variable not present in tfvars

3. Added documentation

• Added "Smoke Testing" section to docs/infrastructure/infra-faq.md
• Documents common smoke test failure scenarios including apex domain misconfiguration
• Provides troubleshooting steps for 404/timeout issues

Testing

Tested locally with:

# Dev environment
scripts/bash/container_app_smoke_test.sh dev <sha> manage-breast-screening.non-live.screening.nhs.uk "" false

# Production environment  
scripts/bash/container_app_smoke_test.sh prod <sha> manage-breast-screening.nhs.uk "" true

## Jira link

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