fix(lasuite): fix OIDC config for People login

- Switch all user-facing app OAuth2 clients to client_secret_post
  (mozilla-django-oidc sends credentials in POST body by default)
- Set LOGIN_REDIRECT_URL=/ so Django redirects to frontend after login
- Add local overlay patch to disable OIDC SSL verification
  (mkcert CA not trusted inside pods; production uses real certs)

base/lasuite/people-values.yaml

@@ -125,6 +125,8 @@ backend:
     ALLOWED_HOSTS:             people.DOMAIN_SUFFIX
     DJANGO_ALLOWED_HOSTS:      people.DOMAIN_SUFFIX
     DJANGO_CSRF_TRUSTED_ORIGINS: https://people.DOMAIN_SUFFIX
+    # Redirect to frontend SPA root after successful OIDC login.
+    LOGIN_REDIRECT_URL:        /
 
 # celeryWorker and celeryBeat intentionally have no envVars here.
 # The desk chart template automatically injects backend.envVars into all