Dev Task: Smoke test after production deployment

**Describe the task**
Catch deployment issues quicker and easier with automated checks on production URLS. Rollback deployments faster so less users are affected if the check fails.

**Acceptance Criteria**
- [ ] Run in GitHub actions after deploying to production
- [ ] The checks should test for http errors on authenticated URLs
- [ ] Merge is blocked if smoke tests fail
- [ ] TBD: define all the endpoints we want to test - e.g.: fire behaviour calculator link

**Additional context**
- Need to find out how to automate a keycloak login
- Need to figure out successful and unsuccessful keycloak redirect flows to be able to smoke test properly

No files or tests are named. Start by reviewing the GitHub Actions deployment path and defining the production endpoints to check, including the fire behaviour calculator link. Confirm the Keycloak login and redirect flows, then verify that authenticated URL failures block the merge and support rollback.

Written by the indexing model from the issue text.