feat: add litellm to new aitooling ArgoCD project (#94)

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

apps/base/litellm/kustomization.yaml

@@ -0,0 +1,23 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - cnpg_cluster.yaml
+  - cnpg_pooler.yaml
+  - deployment.yaml
+  - hpa.yaml
+  - ingress.yaml
+  - namespace.yaml
+  - redis-deployment.yaml
+  - redis-pvc.yaml
+  - services.yaml
+  - vaultauth.yaml
+  - vaultstaticsecret.yaml
+
+configMapGenerator:
+  - name: litellm-config
+    files:
+      - config.yaml=resources/config.yaml
+    options:
+      disableNameSuffixHash: true