QA Build: Corrected Default Post-Login Redirect Domain

Corrected a configuration error in the QA build pipeline so that, after signing in, users on the QA environment are now redirected to the QA mail application instead of being incorrectly sent to the production mail domain.

In the QA deployment configuration, the default redirect URL (NEXT_PUBLIC_DEFAULT_REDIRECT_URL) was mistakenly pointed at the production mail domain (cortex-mail.datagainservices.com) while all other QA app URLs in the same configuration block correctly used the QA-specific domain. This meant a successful login on QA could send users across an environment boundary into production, undermining QA isolation and producing confusing or broken behavior during testing.

QA testers and stakeholders now stay within the QA environment after login, landing on the QA mail app (cortex-maillqa.datagainservices.com) as expected. This removes a source of test confusion and prevents accidental cross-over into the production mail surface from the QA build. There is no impact to the production environment.

• Single-line change in .github/workflows/docker-ecr.yml (the Docker/ECR build pipeline), QA job environment block (1 insertion, 1 deletion).
• Changed the QA build-time env var NEXT_PUBLIC_DEFAULT_REDIRECT_URL from https://cortex-mail.datagainservices.com (production) to https://cortex-maillqa.datagainservices.com (QA).
• The new value now matches the sibling NEXT_PUBLIC_MAIL_APP_URL QA domain already defined in the same block, making the QA configuration internally consistent.
• No application/source code, dependencies, or runtime logic were modified.

Low risk. The change is confined to a single QA-only environment variable in the build workflow and does not touch application code or the production build configuration. Worst case is an incorrect QA redirect target, which is exactly what this corrects; any error would be isolated to the QA environment and verifiable at deploy time.

• Trigger the QA build/deploy and confirm the pipeline completes successfully.
• Log in on the QA environment and verify the post-login default redirect lands on cortex-maillqa.datagainservices.com and no longer on the production cortex-mail.datagainservices.com.
• Confirm the other QA app URLs (mail, vendor, admin) remain unchanged and reachable.
• Smoke-check that production login/redirect behavior is unaffected.