Deploys Open WebUI (chat.k8s.syd1.au.unkin.net) into the open-webui
namespace via the aitooling ArgoCD project. Uses SQLite with a 10Gi
cephrbd PVC for persistence, routes model requests to the existing
litellm deployment, and exposes the UI through the traefik-external
gateway. Credentials (OPENAI_API_KEY, WEBUI_SECRET_KEY) are injected
via VaultStaticSecret from kv/kubernetes/namespace/open-webui/default.
Closes#155
Deploys LiteLLM proxy with CNPG PostgreSQL (3-instance HA), PgBouncer
pooler, and Redis cache. Introduces a dedicated aitooling AppProject and
ApplicationSet to keep AI tooling services separate from platform infra.
Reviewed-on: #94
unkinben