- Adds E2E workflow with deploy/teardown scripts
- Adds Playwright smoke tests for ArgoCD sidebar and app list
- Uses unique release name to avoid collision with shared runner
Fixes PRI-524. Changes push trigger from branches:[main] to branches:['**'] so CI fires on every branch. Adds workflow_dispatch for manual trigger. Adds permissions: contents: read for least-privilege hardening.
All gates clear: CI green, UAT correctly skipped (YAML-only), QA approved (Regina), CTO approved (Nancy).