Replace the single-secret towerops-llm template with one
multi-document YAML covering every Secret the Deployment references:
towerops-secrets, towerops-db, towerops-aws, towerops-redis,
towerops-billing, towerops-llm.
Workflow: copy k8s/secrets.example.yaml to k8s/secrets.yaml (which is
gitignored), fill in real values, kubectl apply. Real values never land
in git.
