Implement Platform Superuser UI and Fix API Role Casing

- Update API to return lowercase roles for frontend compatibility
- Fix Tenant owner lookup in platform admin serializer
- Update frontend App.tsx to match tarball implementation
- Prioritize vite.config.js for HMR support
- Include pending CSP and CORS configuration updates

smoothschedule/pyproject.toml

@@ -141,6 +141,7 @@ dev = [
     "factory-boy==3.3.2",
     "ipdb==0.13.13",
     "mypy==1.18.2",
+    "playwright>=1.56.0",
     "pre-commit==4.5.0",
     "psycopg[c]==3.2.13",
     "pytest==9.0.1",
@@ -192,4 +193,5 @@ dependencies = [
     "sentry-sdk==2.46.0",
     "whitenoise==6.11.0",
     "stripe>=7.0.0",
+    "django-csp==3.8.0",
 ]